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Page 1: Nuclear Physics News - NuPECCeditorial Vol. 27, No. 3, 2017, Nuclear Physics News 319 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search

FEATURING:Nuclear Data • Deuteron Electric Dipole Moment • 0νββ Decay

10619127(2017)27(3)

Nuclear Physics NewsInternational

Volume 27, Issue 3July–September 2017

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Page 3: Nuclear Physics News - NuPECCeditorial Vol. 27, No. 3, 2017, Nuclear Physics News 319 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search

Vol. 27, No. 3, 2017, Nuclear Physics News 1

Editor: Gabriele-Elisabeth Körner

Editorial Board Maria José Garcia Borge, Madrid (Chair) Eugenio Nappi, Bari Rick Casten, Yale Klaus Peters, Darmstadt

Jens Dilling, Vancouver Hermann Rothard, CaenAri Jokinen, Jyväskylä Hideyuki Sakai, Tokyo

Yu-Gang Ma, Shanghai Calin Ur, Bucharest Richard Milner, MIT

Editorial Offi ce: Physikdepartment, E12, Technische Universitat München,85748 Garching, Germany, Tel: +49 89 2891 2293, +49 172 89 15011, Fax: +49 89 2891 2298,

E-mail: [email protected]

Correspondents (from countries not covered by the Editorial Board and NuPECC)Argentina: O. Civitaresse, La Plata; Australia: A. W. Thomas, Adelaide; Brasil: M. Hussein, São Paulo; India: D. K. Avasthi, New Delhi; Israel: N. Auerbach, Tel Aviv; Mexico: E. Padilla-Rodal, Mexico DF; Russia: Yu. Novikov, St. Petersburg; Serbia: S. Jokic, Belgrade; South Africa: S. Mullins, Cape Town.

Nuclear Physics NewsVolume 27/No. 3

Nuclear Physics News is published on behalf of the Nuclear Physics European Collaboration Committee (NuPECC), an Expert Committee of the European Science Foundation, with colleagues from Europe, America, and Asia.

Nuclear Physics News ISSN 1061-9127

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2 Nuclear Physics News, Vol. 27, No. 3, 2017

NuclearPhysicsNews

Cover Illustration: The cover depicts a CAD drawing of the PANDA Detector in the foreground. The background shows the same drawing in kaleidoscopic reflections through a PANDA DIRC bar, which is made of highly polished fused silica – see article on page 24.

Volume 27/No. 3

Contents

EditorialThe NuPECC Long Range Plan 2017: Perspectives in Nuclear Physics

by Angela Bracco .......................................................................................................................................................... 3

Feature ArticlesA New Look to Nuclear Data

by E. A. McCutchan, D. A. Brown, and A. A. Sonzogni ................................................................................................ 5COSY Prepares the First Measurement of the Deuteron Electric Dipole Moment

by Paolo Lenisa and Frank Rankmann ......................................................................................................................... 10Searching for 0νββ Decay in 136Xe: Toward the Ton-Scale and Beyond

by T. Brunner and L. Winslow ....................................................................................................................................... 14

Facilities and MethodsThe Actual AMS Capabilities at the University of Cologne

by Alfred Dewald ........................................................................................................................................................... 20PANDA: Strong Interaction Studies with Antiprotons

by Klaus Peters, Lars Schmitt, Tobias Stockmanns, and Johan Messchendorp ........................................................... 24Twenty Years of VERA: Toward a Universal Facility for Accelerator Mass Spectrometry

by Robin Golser and Walter Kutschera ......................................................................................................................... 29

Meeting ReportsThe 26th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Quark Matter 2017

by Russell Betts, Olga Evdokimov, and Ulrich Heinz ................................................................................................... 35Jefferson Lab Hosts Workshop on New Scientific Applications of its Low Energy Recirculator Facility

by S. Benson and G. Krafft ............................................................................................................................................ 37

News and ViewsESF After ESF: The Launch of Science Connect

by Jean-Claude Worms .................................................................................................................................................. 38An Important Milestone: Groundbreaking Ceremony for the FAIR Accelerator Facility

by Ingo Peter ................................................................................................................................................................. 40

Calendar..................................................................................................................................... Inside back cover

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Vol. 27, No. 3, 2017, Nuclear Physics News 3

19 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search in Europe” was released after approximately 20 months of work for its preparation. From the time it was announced, at the end of 2015, the nu-clear physics community was looking forward to having it ready since this document plays the role of an impor-tant reference and guide for the fi eld for at least the next six years.

The delivery of long range plans (LRPs) represents the core of Nu-PECC’s mission, which is “to provide advice and make recommendations on the development, organisation and support of European nuclear research and of particular projects.” In the past four LRPs were issued, in November 1991, December 1997, April 2004 and December 2010.

The process involved in the prepa-ration of LRPs requires dedicated ef-fort from many physicists of the nu-clear physics community and from all NuPECC Members.

Similar to several countries in the world beyond the European boundar-ies, today Nuclear Physics is defi ned as a fi eld including different research domains sharing the diffi cult but stim-ulating task to study nuclear matter in all its forms and of exploring their possible applications. This knowledge is essential if one wants to address several key issues for the understand-ing of the different stages concern-ing the origin and the evolution of the universe. The subfi elds of nuclear physics defi ned by NuPECC span the areas of nuclear physics and its ap-plications: Hadron Physics, Proper-ties of Strongly Interacting Matter (at extreme temperatures and baryon number density), Nuclear Structure and Dynamics, Nuclear Astrophysics, Symmetries and Fundamental Interac-tion, as well as Applications and Soci-etal Benefi ts.

Two Conveners and three Liaison Members of NuPECC were assigned to each Working Group corresponding to one of the subfi elds given above. The Working Groups were given the charge to delineate the most exciting physics in their subfi elds, to high-light recent achievements and future perspectives. Draft reports from the Working Groups were presented and discussed in internal workshops and at NuPECC Meetings.

A Town Meeting to discuss the NuPECC LRP was held at the “darm-

stadtium” in Darmstadt, from 11–13 January 2017. The Town Meeting was attended by almost 300 participants, including many young scientists. The programme contained, in addition to the presentation of the Working Groups, sessions on future facilities: FAIR, the ISOL facilities (SPIRAL2, ISOLDE, and SPES), ELI-NP, NICA, and the Dubna Superheavy Element Factory, as well as a presentation for CERN from its scientifi c director. For the international context the over-views given by the Chairs of NSAC (USA) and ANPhA (Asia) were much appreciated. The Town Meeting was concluded by a general discussion.

The recommendations with their wording were extensively discussed, not only at the town meeting but also at the following NuPECC meetings. It is not possible here, due to space limits, to quote them directly in their complete form and thus the reader is invited to read our webpage (http://www.nupecc.org/pub/lrp2017.pdf).

In short, the recommendation sec-tion includes the following: (1) a rec-ommendation for the construction and operation of the fl agship facility FAIR with its experimental programme at the four scientifi c pillars APPA, CBM, NUSTAR, and PANDA; (2) support for construction, augmentation, and exploitation of world-leading ISOL facilities in Europe; (3) the exploita-tion of the existing and emerging fa-cilities (the latter being ELI-NP and NICA); (4) support for ALICE and the heavy-ion program at the LHC with the planned experimental up-grades; (5) support to the completion

The NuPECC Long Range Plan 2017: Perspectives in Nuclear Physics

NuPECC Long Range Plan 2017 Perspectives in Nuclear Physics

The views expressed here do not represent the views and policies of NuPECC except where explicitly identifi ed.

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of AGATA in full geometry; (6) Sup-port for Nuclear Theory. In addition, the particular role of R&D for future projects and of education and training are underlined in the recommendation section.

In the introduction chapter one can fi nd special mention to the contribu-tion received by the European Com-mission to the different facilities, the ones focusing on hadron physics and the ones on nuclear structure and as-trophysics (presently in the ENSAR2 integrated activity). Concerning the more general scientifi c context, in which the Nuclear Physics infrastruc-tures are placed, the relation of Nu-PECC with ESFRI is very important and fruitful.

Last but not least, in the introduc-tion and also in various chapters, the role of international collaborations

worldwide, outside Europe (the larg-est fraction being in the United States and Japan), is underlined, resulting in major achievements in the fi eld. These collaborations are expected to continue and to be reinforced in the future.

Let me conclude by saying that this editorial is not only intended to inform on the release of the long range plan, but it is also intended to thank all the people involved directly or more indi-rectly in this process. Now these ac-tive players in the fi eld are expected to further enhance the vitality of the fi eld by using this long range plan as a key tool for this purpose. Indeed, it will be very important in the coming years to implement the objectives outlined in the recommendations, in particular also those that go beyond the capabili-ties of an individual country.

AcknowledgmentsIn addition to the thanks to the

many scientists contributing to the preparation of this long range plan, I convey special thanks to Karin Füssel (from GSI/FAIR, Darmstadt) for the organization of the town meeting and to Mara Tanase (from ELI-NP, Bucha-rest) for the technical editing and the layout of the volume.

ANGELA BRACCO

University of Milan;NuPECC Chair

_________________________________________________________________________________________________

READ LEARN DISCUSS PARTICIPATE

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IntroductionDatabases of evaluated nuclear data form a cornerstone

on which we build academic nuclear structure physics, reaction physics, astrophysics, and many applied nuclear technologies. In basic research, nuclear data are essential for selecting, designing, and conducting experiments, and for the development and testing of theoretical models to understand the fundamental properties of atomic nuclei. Likewise, the applied fields of nuclear power, homeland security, stockpile stewardship, and nuclear medicine all have deep roots requiring evaluated nuclear data. Each of these fields requires rapid and easy access to up-to-date, comprehensive, and reliable databases. The Department of Energy (DOE)–funded U.S. Nuclear Data Program is a specific and coordinated effort tasked to compile, evalu-ate, and disseminate nuclear structure and reaction data such that it can be used by the worldwide nuclear physics community.

Overview of Our DatabasesWithin the U.S. Nuclear Data Program (USNDP), data

are filtered into two primary databases; the Evaluated Nuclear Structure Data File (ENSDF) containing nuclear structure and decay data, and the Evaluated Nuclear Data File (ENDF/B) containing nuclear reaction data.

ENSDF [1] contains experimentally determined nuclear structure and decay data for all known nuclei. The results derived following each specific nuclear reaction and de-cay mode are individually cataloged and then combined in a critical analysis of all measurements to derive recom-mended properties for each quantum state and its decays. The uncertainties on each derived quantity are carefully evaluated. ENSDF is the only database in the world of this kind and is updated on a monthly basis. The evaluated data from ENSDF are used in a number of tools utilized by the nuclear physics community, including Monte Carlo codes like MCNP and GEANT, medical dosimetry files, Ortec and Canberra isotope identification software, Nuclear Wal-let Cards, and more.

The ENDF/B library [2] contains nuclear reaction data mainly for use in nuclear applications, including cross-sec-tions, outgoing particle distributions, fission product yields, as well as atomic reaction data and decay data. Users of ENDF/B data frequently access the data through applica-

tion codes and often the users are not even aware that they are using ENDF/B data libraries (such as various applica-tion-tailored cross-section libraries). The most well-known applications include general particle transport codes used in nuclear reactor, radiation shielding and health physics applications (e.g., MCNP6, SCALE, GEANT4); isotope burn-up codes used for the time-dependent nuclear reactor analyses, nuclear waste managements, and radiochemical applications (e.g., ORIGEN, CINDER); and other appli-cation code systems that use covariance data to estimate nuclear data uncertainty in application metrics (e.g., TSU-NAMI, WHISPER).

The U.S. Nuclear Data Program supports two additional databases that complement and underpin the primary da-tabases; the Nuclear Science References Database (NSR) [3] and the Exchange FORmat Database (EXFOR) [4]. NSR contains bibliographic information on low- and in-termediate-energy nuclear physics articles including more than 220,000 publications and secondary references span-ning the 100 years of nuclear physics research. The EX-FOR library includes a complete compilation of experi-mental neutron-induced reactions, selected compilations of charged-particle-induced and photon-induced reactions, and assorted high-energy and heavy-ion reaction data. The EXFOR library is the most comprehensive collection of experimental nuclear reaction data available. The USNDP coordinates compilation of EXFOR data experiments per-formed in North America.

The newest addition to the supporting databases is XUNDL (eXperimental Unevaluated Nuclear Data List), a database [5] containing critical compilations of current journal articles on experimental nuclear structure and radio-active decay data presented in the same format as ENSDF. It takes, on average, 7–8 years to revisit and re-evaluate all 3,300 nuclei currently contained in ENSDF. XUNDL was developed to complement ENSDF and provide users with data from publications which have not yet been included into ENSDF. Presently, over 15 experimental journals are scanned on a frequent basis and relevant articles incor-porated into XUNDL within two months of publication. Supplemental material provided by authors and associated with published papers can also be included. Such additions are highly encouraged, particularly in instances where the publication has a length limitation.

A New Look to Nuclear DataE. A. MccutchAn, D. A. Brown, AnD A. A. Sonzogni

National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY, USA

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Figure 2. NuDat search page for making queries of specific nuclear prop-erties in ENSDF.

Figure 1. Q value for beta-delayed neutron emission for the entire chart of nuclides as plotted using the Nu-Dat application.

Interacting with Structure DatabasesAll databases can be quickly and easily searched using

Web applications available at the National Nuclear Data Center (NNDC) website at www.nndc.bnl.gov. We are continually developing new tools to make data access and visualization easier. We try to be responsive to user needs

and encourage community participation in improving the databases and corre-sponding software. In 2016, more than four million electronic retrievals were made from the NNDC website, access-ing various databases and online appli-cations. By far, the most popular prod-uct (at over 60% of the total retrievals) is the application NuDat. NuDat pro-vides users many options for displaying the nuclear structure and decay data in ENSDF, from the entire nuclear chart, to a single nucleus, and from tabular nu-

merical data to sophisticated plotting capabilities. Many nuclear properties can be visualized by selecting from op-tions at the top of the chart; Figure 1 gives an example using the Q value for beta-delayed neutron emission. The plots have the option for zooming in to smaller regions of the chart or selecting a single nucleus. NuDat also can be

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used to search all of ENSDF for basic properties of nu-clei. The search page is illustrated in Figure 2, where con-ditions on energy, spin, parity, half-life, transition mul-tipolarity and more can be placed. A particularly useful feature in an experimental setting is the ability to search for gamma-ray transitions which are known to come in coincidence.

New plotting features are currently being incorporated into NuDat. As an example, a common observable used as an indicator of deformation in nuclei is the ratio of the ex-citation energy of the fi rst 4+ state to the fi rst 2+ state (the R4/2 ratio) in even-even nuclei. Figure 3 (left) illustrates the previous plotting capabilities of NuDat for the R4/2 ratio.

While some trends are evident, such as increasing values as one moves away from closed shells, the fi ner details are not immediately obvious from the two-dimensional plot. A new feature in NuDat now allows observables, like the R4/2ratio, to be automatically plotted as a function of both pro-ton and neutron number. Here is where new physics can be quickly observed, with the large gap in the plot as a func-tion of proton number (right panel) indicating the presence of a sub-shell closure [6]. Such plotting features are avail-able for a number of basic observables. For the future, more extensive plotting capabilities are being explored, includ-ing, for example, plotting one measured quantity versus another.

The traditional way of visualizing the levels in a nucleus and their decay has been to use horizontal lines to indicate excited levels and vertical arrows to indicate gamma-ray transitions. Again, in an attempt to provide users with a different perspective, the standard plotting capabilities in NuDat have been expanded to include for each nucleus the option to generate plots of excitation energy as a function of spin. An example of this type of plot is given in Figure 4 for 194Pb. The user will have the option to join individual states by their gamma-decay branching ratio, as done in Figure 4, or by transition strengths (M1, E2, etc.). In this example, the changes in shape as a function of angular momentum can be clearly identifi ed.

New Release of ENDF/B: ENDF/B-VIII.0As mentioned above, the ENDF/B library contains

nuclear reaction data for transport and other applications. ENDF/B is the product of the Cross Section Evaluation Working Group (CSEWG), a collaboration that has been active since 1967. It has been 50 years since the release of

Figure 3. (Left) Previous plotting option in NuDat displaying the R4/2 ratio in a region around 100Mo. New plotting options are found in the middle and right panels where the same R4/2 ratio will be automatically displayed as a function of both neutron and proton number.

Figure 4. Plot of excitation energy as a function of angular moment for levels in 194Pb. States are connected by their branching ratios, with the width of the line proportional to the intensity.

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ENDF/B-I. Currently CSEWG is preparing a new release: ENDF/B-VIII.0

This new ENDF/B-VIII.0 Library release incorporates work from across the United States and the international nuclear science community over the last six years, most no-tably with Europe (JEFF), Japan (JENDL), South Korea, and the International Atomic Energy Agency (IAEA). This Library is being issued in the traditional ENDF-6 format, as well as in an alternative new Generalized Nuclear Data (GND) format. ENDF/B-VIII.0 is due late 2017.

Major changes to ENDF/B-VIII.0 include:

• A new Neutron Standards evaluation• New standards-level full evaluations from the CIELO

pilot project: 235, 238U, 239Pu, 56Fe, 16O, and 1H • Many new and improved neutron evaluations • New atomic reaction data • Many new thermal scattering evaluations • Improvements to charged particle reactions

ENDF/B-VIII.0 is the best-performing ENDF/B library to date. ENDF/B performance is typically measured by the agreement between simulations of small zero power nu-clear reactors (critical assemblies) and their experimental realization. The fi gure of merit in these comparisons is the keff, namely the ratio of neutron gain to loss. Figure 5 shows the cumulative χ2 from a series of simulations of these criti-cal assemblies.

New Developments in Nuclear Data SheetsTraditionally, nuclear structure evaluations are docu-

mented and published in Nuclear Data Sheets (NDS), a monthly journal published by Elsevier Science. NDS dates back to 1965 and continues to thrive and be a well-cited resource within the community. However, the format of NDS has remained nearly the same for decades. Based on user input and feedback, the February 2017 issue [7] of NDS introduces a new layout and several improvements to the presentation of data. The most signifi cant change is in the presentation of tabular data. The ENSDF recommended data are presented in two tables, one describing level prop-erties and the other displaying the gamma and E0 transition decays. Previously, these two tables were distinct, linked only by the excitation energy of the initial level. To allow the tables to be used more independently, the gamma-ray table has been expanded, to provide the user with informa-tion on the spin of the parent level, as well as the excitation energy and spin and parity of the fi nal level. The font for all

Figure 5. Cumulative χ2 of ENDF/B library performance. Each tick on the x-axis represents one critical assembly case. The y-axis is the cumulative χ2 comparing perfor-mance of the simulation of each critical assembly to the experimental keff . Lower cumulative χ2 indicates better per-formance.

Figure 6. New format of the gamma-ray table available in Nuclear Data Sheets and on-line through the ENSDF search application. New columns (indicated by the red squares) include the Jπ of the initial level, as well as the energy and Jπ of the level to which the gamma-ray decays.

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tables and text has also been increased for ease in reading. An example of the new gamma table is given in Figure 6. Recently, all of ENSDF was made available for download-ing with this new layout and PDF format which can be ob-tained at www.nndc.bnl.gov/ensdf.

Improvements have also been made to the presentation of level schemes and band drawings. An example is pre-sented in Figure 7. For the sake of clarity, the requirement of plotting the excitation energies to scale has now been relaxed, and levels are separated such that their decay is legible. Color coding has been added, so that one can easily get an idea for the stronger and/or weaker transitions in the decay. Finally, decay paths involving particle emission are now incorporated into the drawings, for example, in Fig-ure 7, the beta-delayed neutron branch is indicated by the hatched region.

NDS is not limited to publishing just nuclear structure evaluations. Since 2006, the journal has devoted one spe-cial issue a year to nuclear reactions, with the aim to pro-vide a venue for publication of key papers on reaction eval-uations that are too extensive or detailed for other journals. These issues can have a large impact, the paper detailing the release of ENDF/B-VII.0 [8] has over 1,600 citations (Google Scholar), while the ENDF/B-VII.1 paper [2] has

over 940 citations (Google Scholar). Submissions relating to nuclear structure or reaction data are welcomed and au-thors with articles with relevance to Nuclear Data Sheets should contact the editor for additional information.

Future OutlookThe history of nuclear physics has always been data

driven and has shown that systematic studies of nuclear properties can lead to major advances in our understanding of how nuclei work. An exciting time is upon us, where new, modern facilities around the world are providing huge amounts of data in a new terrain of the nuclear chart. Vastly increased computing power is enabling more fundamental theoretical models based on real nuclear forces. The Internet now allows us to share these new results at unprecedented speed. With these types of advances, the rapid collection, correlation, evaluation, and dissemination of data is ever more important. The U.S. nuclear data program is eager to work closely with the nuclear physics community to ensure that all data are promptly and reliably incorporated into the databases in order to pave the way for new scientific break-throughs. To exploit the full potential for scientific discov-ery will also require the development of innovative soft-ware tools for display, extraction, and manipulation of the evaluated data and feedback from the users on their needs is highly requested.

AcknowledgmentsThe authors are grateful to their colleagues within the

U.S. Nuclear Data Program and the International Network of Nuclear Structure and Decay Data Evaluators for their contributions to the databases and applications presented in this article. In particular, we thank J. Chen and B. Singh for their efforts in developing the new program for PDF displaying of ENSDF. This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, Office of Science, under contract DE-AC-02-98CH10886.

References1. ENSDF database (Evaluated Nuclear Structure Data File),

www.nndc.bnl.gov/ensdf/2. M. B. Chadwick et al., Nucl. Data Sheets 112 (2011) 2887.3. B. Pritychenko, Nucl. Data Sheets 120 (2014) 291, www.nndc.

bnl.gov/nsr4. N. Otuka et al., Nucl. Data Sheets 120 (2014) 272. 5. XUNDL database (eXperimental Unevaluated Nuclear Data

List), www.nndc.bnl.gov/ensdf/ensdf/xundl.jsp6. R. B. Cakirli and R. F. Casten, Phys. Rev. C 78 (2008) 041301. 7. J. Chen, Nucl. Data Sheets 140 (2017) 1. 8. M.B. Chadwick et al., Nucl. Data Sheets 107 (2006) 2931.

Figure 7. Example of new decay drawing available online and in the Nuclear Data Sheets journal.

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One of the most intriguing questions in cosmology and perhaps in all of physics is: “Why is there so much matter in the Universe and so little antimatter?” Until today, there is no evidence for any primordial antimatter within our gal-axy or even beyond. There is no indication for any form of co-existence of matter and antimatter in clusters or galaxies within our Universe. Hence, it is usually concluded that our visible Universe is made entirely of matter and is intrin-sically matter non-symmetric. According to the combined Standard Models of cosmology and particle physics it is expected that at the end of the inflationary epoch—follow-ing the Big Bang—the number of particles and antiparticles were in extreme balance, yet somehow the laws of phys-ics contrived to act differently on matter and antimatter in order to generate the current imbalance. Interestingly, one of the necessary physics mechanisms required for such ef-fects—namely CP-violation—is very small in the Standard

Model (SM) of particle physics and thus is only able to ac-count for a tiny fraction of the actual asymmetry.

While particle physics at accelerators celebrated its lat-est success with the discovery of the Higgs boson, culmi-nating in a series of discoveries all consistent with the SM, the chances have grown in recent years that new physics could be at mass scales beyond the reach of current or fu-ture collider experiments. This prospect, in combination with astrophysical observations (e.g., dark matter, neutrino oscillations), not explained by the SM has stimulated in-terest in high-precision physics. One such search for new physics is the quest for electric dipole moments (EDMs) in fundamental particles.

An EDM originates from a permanent electric charge separation inside the particle. In its center-of-mass frame, the ground state of a subatomic particle has no direction at its disposal except its spin, which is an axial vector, while

COSY Prepares the First Measurement of the Deuteron Electric Dipole MomentPaolo lenisa University of Ferrara and INFN, Ferrara, ItalyFrank rathmann

Institut fur Kernphysik, Forschungszentrum Julich, Julich, Germany

Figure 1. Left: Naïve representation of a fundamental particle as a spherical object with an asymmetric charge density (upper left). The particle mirror image is represented on the right, and its time-reversal at the bottom. The particle spin defines (s) a direction in space. Both P and T transformations leave the magnetic dipole moment (μ) antiparallel to the spin while change the relative orientation of the electric dipole moment (d). Therefore, the original particle can be distin-guished from its mirror or time reversal image. Right: Experimental upper limits for the EDMs of different particles (red bars) plotted together with the prediction from SUSY (blue bands) and the Standard Model (green bands). No experimental limit exists yet for the deuteron.

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the charge separation (EDM) corresponds to a polar vector. If such a particle possesses an EDM, it must violate both parity (P) and time-reversal (T) invariance (Figure 1, left panel). If the combined CPT symmetry is to be valid, T vio-lation also implies breaking of the combined CP symmetry. The Standard Model predicts the existence of EDMs, but their sizes fall many orders of magnitude below the sensi-tivity of current measurements and still far below the ex-pected levels of projected experiments. An EDM observa-tion at a much higher value might be interpreted as a sign of new physics beyond the current Standard Model (BSM).

Researchers have been searching for EDMs of neutral particles, especially neutrons, for more than 60 years, but, despite a constant increase in sensitivity, the experiments have come up only with upper bounds, nevertheless pro-viding useful constraints on BSM theories (Figure 1, right panel). More recently, a new class of experiments based on storage rings has been proposed to improve the sensitivity of the measurements and eventually be able to measure the EDM of charged particles (such as the proton, deuteron, or helion).

The measuring principle is straightforward: a radial electric field is applied to an ensemble of particles circulat-ing in a storage ring with their polarization vector (or spin) initially aligned with their momentum direction. The exis-tence of an EDM would generate a torque that slowly ro-tates the spin out of the plane of the storage ring and into the vertical plane (Figure 2). This slow change in the vertical polarization is measured by sampling the beam with elas-tic scattering off a carbon target and looking for a slowly increasing left-right asymmetry in the scattered particle flux. For an EDM of 10–29 e·cm and an electric field of 10 MV/m, this would happen at an angular velocity of 3·10–9

rad/s (about 1/100 of degree per day!). This requires the measurement to be sensitive at a level never reached before in a storage ring. These requirements imply that for a sta-tistically significant result, the polarization in the ring plane must be kept for times on the order of a thousand seconds during a single fill of the ring and the scattering asymmetry from carbon must reach levels above 10‒6 in order to be measurable within a year of running.

At the Cooler Synchrotron COSY located at the For- schungszentrum-Jülich (FZJ) (Figure 3), the JEDI Collabo-ration (http://collaborations.fz-juelich.de/ikp/jedi/index.shtml) is working on a series of feasibility studies for the EDM experiment in a to-be-built dedicated storage ring. The COSY ring, able to store both polarized proton and deuteron beams, is an ideal machine for the development and commissioning of the necessary technology.

Following the commissioning of a measurement sys-tem that stores the clock time of each recorded event in the beam polarimeter, some major achievements have been already realized. The polarized beam is injected into COSY with the polarization vertical. Operating a radio-frequency solenoid for a brief period turns the polarization into the ring plane and subsequently the measurements are started. Above all, it was possible to unfold for the first time the rapid rotation of the polarization in the ring plane (~120 kHz) arising from the gyromagnetic anomaly. The spin tune (i.e., the number of spin precessions per turn) has been

Figure 2. Measuring principle of a charged particle EDM in a storage ring. A radial electric field is applied to an ensemble of particles circulating in a storage ring with po-larization vector aligned to their momentum: the existence of an EDM, would generate a torque that slowly rotates the spin out of the ring plane into the vertical direction.

Figure 3. The COSY storage ring at the Forschungszen-trum Julich.

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measured with a precision better than 10–10 in a cycle of 10 seconds that possibly represents the most precise measure-ment ever performed in a storage ring (Figure 4, left) [1]. It was also demonstrated that, by determining the errors in the polarization direction and feeding this back to make small changes in the ring radio-frequency, the direction of the po-larization may be maintained at the level of 0.1 radian for any chosen time period. This is another requirement needed for managing the polarization in the ring for the EDM ex-periment. Another milestone was the achievement of polar-ization lifetimes in the ring plane longer than 1,000 s (Fig-ure 4, right) [2]. Maintaining the polarization in the ring plane requires the cancellation of effects that may cause the particles in the beam to differ from one another. Bunching and electron cooling the beam serves to remove much of this spurious motion. However particle path lengths around the ring may differ if particles in the beam have transverse oscillations with different amplitudes. The effect of these differences on polarization decoherence may be removed by applying correcting sextupole fields to the ring. As a re-sult, the polarization lifetimes now reach the required dura-tion for the EDM experiment.

In 2016 the European Research Council awarded an Advanced Research Grant to the Jülich group, supporting further R&D efforts. The goal of the project is to conduct the first ever measurement of the deuteron EDM. Since at COSY the polarization cannot be maintained parallel to its velocity, a novel device called a radiofrequency Wien filter [3] will be installed in the ring to slowly accumulate the EDM signal: the filter influences the spin motion without acting on the particle’s orbit. The idea is to exploit the elec-tric fields created in the particle rest system by the mag-netic fields of the storage-ring dipoles (Figure 5). As the

particles’ spin precesses with a different frequency with re-spect to the velocity, the net contribution to the polarization buildup coming from the motional E-fields per turn would average to zero. The RF-Wien filter, synchronized with the spin precession frequency, would restore the parallelism between spin and momentum and allow the polarization build-up to take place. A prototype of the radiofrequency Wien filter has been successfully commissioned and was tested at COSY in 2014. In the test, the B field was oriented in the radial direction, and its force on the stored deuter-ons was perfectly cancelled by the vertical electric one: the device could be used to continuously flip the vertical po-larization of a 970 MeV/c deuteron beam without exciting any coherent beam oscillations. In the EDM experiment,

Figure 4. Achievements at the COSY Storage Ring. Left: deviation of the spin tune νs, which is defined as the number of spin precessions per turn, as a function of the number of turns in the ring. At t = 38 s (about 28 × 106 turns), the interpo-lated spin tune amounts to 16097540628.3 ± 9.7 × 10–11, which represents the most precise measurement of this quantity ever performed. Right: One of the longest polarization lifetimes recorded for the COSY ring. Measurements made at four separate times (to conserve beam) are matched to a depolarization curve that assumes a Gaussian distribution of trans-verse oscillation amplitudes. The half-life of the polarization is 1173 ± 172 s, which is three orders of magnitude longer than previous results using electron beams.

Figure 5. First measurement of the deuteron EDM as planned at COSY. The spin precesses in the vertical mag-netic field of the dipoles and feels a torque caused by the interaction of the EDM with the electric motional field. To allow for polarization buildup to occur, an RF-Wien filter will be used to control the relative phase between spin and momentum.

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the radiofrequency Wien filter will be rotated by 90° around the beam axis, so that the B field will point in the verti-cal direction and consequently act on the spins of the par-ticles precessing in the horizontal plane. To accomplish to the task, the frequency of the Wien filter will be locked to the spin motion of the particles by a novel developed spin-feedback system.

The most significant challenges will come from the management of systematic errors. Small imperfections in the placement and orientation of ring elements may cause stray field components that generate the accumulation of an EDM-like signal. The experiment is most sensitive to radial magnetic fields and vertical electric fields. Similar effects may arise through the non-commutativity of spurious rota-tions within the ring system. Efforts are underway to model these effects through spin tracking supported with beam testing. Eventually, many such effects may be reduced or eliminated by comparing the signal accumulation rates seen

with beams traveling in opposite directions in the storage ring.

The commissioning of the RF-Wien Filter and the dem-onstration of its control over the particles’ spin will rep-resent a fundamental milestone towards the design and realization of the final high-precision ring with a EDM sen-sitivity goal of 10–29 e.cm or even better. This will neces-sarily require the use of clockwise (CW) and counterclock-wise (CCW) beams to remedy systematic errors like: radial magnetic fields, non-radial electric fields, vertical quadru-pole misalignments, rf-cavity misalignments and unwanted field components. As a matter of fact, the main systematic error coming from an unwanted spin precession due to the magnetic dipole moment in radial magnetic fields (which is indistinguishable from the EDM signal) can be controlled to a very high accuracy in the CW-CCW scheme, as the very same radial magnetic field causes forces in different directions for two opposite beams (Figure 6).

Also in view of the possible construction of a dedicated EDM ring, COSY constitutes an important test facility of many EDM related key technologies. Besides polarimetry, beam position monitoring and active control systems, also the design of electrostatic and electromagnetic deflectors benefits by direct test in a storage ring. In addition, checks for systematic errors can be undertaken for further develop-ments and applications.

Recently CERN also demonstrated interest in the per-spectives offered by storage-ring EDM searches. An EDM kickoff meeting took place on 13–14 March 2017 at CERN and a working group has been being established to investi-gate the option.

ORCIDPaolo Lenisa

http://orcid.org/0000-0003-3509-1240

References1. D. Eversmann et al., Phys. Rev. Lett. 115 (2015) 094801.2. G. Guidoboni et al., Phys. Rev. Lett. 117 (2016) 054801.3. J. Slim et al., Nucl. Instr. Meth A 828 (2016) 116.

Figure 6. Concept of a dedicated ring for the measurement of an electrical dipole moment (proton case). Two particle beams circulate in opposite directions in a radial electric field with polarization vector aligned to their momentum: the existence of an EDM would generate a torque that slowly rotates the spin out of the plane of the storage ring into the vertical direction. Note that for a beam impulse of p = 0.701 GeV/c (magic momentum) there is no spin precession in the accelerator plane due to the magnetic moment.

View current and forthcoming physics titles:

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The quest for neutrinoless double-beta decay (0νββ) is a promising experimental approach to search for lepton num-ber violation in weak interactions, a key ingredient in gen-erating the matter-antimatter asymmetry through models of Leptogenesis. The 136Xe-based 0νββ experiments Kam-LAND-Zen and EXO-200 currently set the most stringent limits on this process using two very different techniques. Each are preparing the next generation experiment, which will search for 0νββ in the parameter space corresponding to the inverted hierarchy for neutrino mass. Both of these techniques scale well to larger volumes while incorporating interesting new techniques. We present the status of current and next generation experiments of these collaborations and present two developments with the potential to identify ββ decay events.

IntroductionNeutrinos are one of the least understood particles in

the universe, yet almost as abundant as photons. They only interact weakly, which makes experiments aimed at deter-mining their properties extremely difficult. Neutrinos are electrically neutral, which makes them unique among all known fermions and offers the possibility that they may in fact be Majorana particles (i.e., neutrino and anti-neutrino could be identical particles). The only currently feasible approach to determine the Majorana nature of neutrinos is by searching for lepton number violating decays, such as neutrinoless double-beta decay (0νββ). A positive observa-tion of 0νββ would demonstrate that lepton number is not a conserved quantity in weak interactions and prove that the neutrino is a Majorana fermion. This new physics would provide a mechanism through Leptogenesis for generating the matter–antimatter asymmetry in the universe, answer-ing the question of why we live in a matter-dominated uni-verse.

Double beta decay occurs in 35 isotopes [1], but only a few of them are of interest for 0νββ searches due to con-siderations of endpoint and natural abundance (see Ref. [2] for a list of isotopes and past, current, and future ββ decay experiments). The Enriched Xenon Observatory (EXO)

and KamLAND-Zen experiments are searching for a 0νββ decay in 136Xe. Xenon-136 has a relatively high natural abundance of 8.6%, which makes enrichment easier, and the Q value of 2.5 MeV is above most naturally occurring backgrounds.

Once observed, the effective Majorana neutrino mass <mββ> can be extracted from the 0νββ rate

Γ01ν/2 = G0ν|M

0ν|2|<mββ>|2, (1)

where G0ν is the phase-space factor and M0ν is the nuclear matrix element. Both values are provided by nuclear theory, although with sizable differences between nuclear matrix elements calculated in different theoretical frameworks. The sensitivity of experiments is quoted in terms of <mββ> as shown in Figure 1 with increased experimental sensitiv-ity corresponding to smaller <mββ>.

Searching for 0νββ Decay in 136Xe: Toward the Ton-Scale and BeyondT. Brunner Physics Department, McGill University, Montreal, QC, Canada and TRIUMF, Vancouver, BC, CanadaL. WinsLoW

Laboratory for Nuclear Science, Massachusetts Institute of Technology, MA, USA

Figure 1. Measured (solid) and projected (hatched) effective Majorana neutrino mass sensitivity limits of EXO-200 and KamLAND-ZEN (KLZ) as function of the lightest neutrino mass eigenstate mmin. The sensitivity of next gen-eration 136Xe 0νββ decay experiments is shown as cross-hatched band. The allowed parameter space from oscilla-tion experiments is shown as red and blue bands for normal and inverted mass hierarchy, respectively.

-210

-310

-210

-110

-210

-110

010

-110

010

Inverted Mass HierarchyNormal Mass Hierarchy

-410

-310

-410

-310

EXO-200 current

EXO-200 projected

KLZ current

KLZ 800 projected

Projected SensitivityNext Generation Detectors

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The EXO and KamLAND-Zen collaborations are cur-rently developing concepts of next generation experiments in parallel to the operation and data taking with the current detectors. Current and future developments will be pre-sented in the following sections.

Current ResultsThe current half-life limits of EXO-200 and KamLAND-

ZEN were used to extract the effective Majorana neutrino mass-limit region using nuclear matrix elements from [3, 4], which is shown as solid bands in Figure 1. Projected sensitivities of EXO-200 final and KamLAND-Zen 800 are shown as hatched bands. KamLAND-Zen and EXO-200 currently provide two of the most stringent limits on the 0νββ-decay half-life, independent of the choice of isotope.

EXO-200EXO-200 is a liquid xenon time-projection chamber

(TPC) located at the Waste Isolation Plant Project (WIPP) in New Mexico, USA. The detector consists of two al-most identical TPC halves with a shared, optically trans-parent, cathode [7], which creates two drift regions with a drift field of ~400 V/m. The detector is filled with 175 kg of liquid xenon enriched to ~81% in the isotope 136Xe. A sectioned view of an engineering rendering of EXO-200 is shown on the right side in Figure 2. Radioactive decays and cosmic radiation deposit energy in the detector volume, ionizing the xenon and creating scintillation light and free electrons, which are drifted toward the anode wire planes. Both scintillation light and electric charge are read by large-area APDs and two wire planes, called u and v wires, re-spectively. Scintillation-light and charge measurement are

used to fully reconstruct the energy of each event, its loca-tion within the detector volume, and its multiplicity, that is, the number of locations at which energy was deposited in each event. Beta events deposit energy predominantly in one location (single-site events), while γs scatter depos-iting energy at multiple locations (multisite events). Fig-ure 2 shows the single-site energy spectrum of EXO-200, which is dominated by 2νββ events. The multisite spectrum (not shown) mainly consists of γ events, which are used to constrain the background models of the single-site fit. Alpha events mainly emit scintillation light and are easily identified and discriminated. The event location allows to optimize the sensitivity of a physics search by adjusting the fiducial volume and taking advantage of the self-shielding of xenon.

In phase I of data taking with EXO-200, an energy reso-lution of 1.53 ± 0.06% at the Q value was achieved [5]. This data set allowed the measurement of the 2νββ half life T1/2

2ν = 2.165 ± 0.061 · 1021 years [6], which is the slowest decay rate ever measured directly, and put a limit on the 0νββ half life of T1/2

0ν > 1.1 × 1025 years at the 90% confi-dence level (C.L.) with a sensitivity of 1.9 · 1025 years at an exposure of 100 kg-year [5].

In early 2014, two independent incidents at the WIPP site caused the mine operation and EXO200 to halt, and only in early 2016 EXO-200 phase II low-background data taking could resume. During this down time part of the detector’s front-end electronics was upgraded and a “de-radonator” was installed to reduce the radon concentration in the air gap between the outer cryostat and low-radio-active lead shielding. These upgrades along with analysis improvements resulted in a 2-fold increase of EXO-200’s

Figure 2. (left) EXO-200 phase I single-site energy spectrum. The insert is zoomed in at the region around the Q value. (right) Sectioned view of the EXO-200 TPC with annotations to main features of the detector. The Teflon sheet in front of the field-shaping rings reflects scintillation light and increases the avalanche photo diodes’ (APDs) acceptance. Figures adapted from Refs. [5, 6].

Phase I

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Inner Balloon(3.08 m diameter)

Photomultiplier Tube

Outer Balloon(13 m diameter)

Buffer Oil

Chimney

Corrugated Tube

Suspending Film Strap

Film Pipe

Xe-LS 13 ton(300 kg Xe)

Outer LS1 kton

136

ThO W Calibration Point2

Visible Energy (MeV)1 2 3 4

Even

ts/0.

05M

eV

1−10

1

10

210

310

410 DataTotalTotal

U.L.)ββν(0ββνXe 2136

ββνXe 0136

(90% C.L. U.L.)

Ag110m

Bi210Th+232U+238

K40Kr+85Po+210+IB/ExternalSpallation

(a) Period-2

sensitivity to 3.7 × 1025 years and a limit on the 0νββ half life of T1/20ν > 1.8 × 1025 years at the 90% C.L. for the full data set [19].

KamLAND-ZenKamLAND is a monolithic liquid scintillator detector

located in the Kamioka Mine in Japan. The original oscilla-tion experiment used one kiloton of liquid scintillator con-tained in a 6.5 m radius balloon to detect antineutrinos from Japan’s nuclear reactors. KamLAND-Zen uses this large scintillating volume as an active shield for a central vol-ume of enriched xenon-doped liquid scintillator contained in an inner balloon with a radius of 3 m. A schematic of the KamLAND-Zen detector is shown in Figure 3.

The inner balloon was installed in 2011, the same year as the great east Japan earthquake and subsequent Fukushima power plant disaster. The first phase of data taking from 12 October 2011 to 14 June 2012 with an exposure of 89.5 kg-year of 136Xe showed a significant contamination from 110mAg, a fission product. A purification campaign success-fully removed this background. The post-purification phase collected data from 11 December 2013 to 27 October2015, corresponding to an exposure of 504 kg-year and a sensi-tivity of 5.6 × 1025 yrs. It set a limit of T1/2

0ν > 9.2 × 1025 years and when combined with the pre-purification data set leads to a limit of T1/2

0ν > 1.01 × 1026 at the 90% C.L. This is the leading limit for 0νββ and KamLAND-Zen is the first experiment to surpass the 1026 year half-life.

The success of KamLAND-Zen has shown that the ad-vantages of the liquid scintillator technique: large masses,

self-shielding, and fully contained energy depositions can make up for the relatively poor energy resolution. The Ka-mLAND-Zen experiment is in the process of installing a new slightly larger mini-balloon to hold ~800 kg of 136Xe. Data taking for KamLAND-Zen 800 is expected to start in the next year. This is the first step in KamLAND-Zen’s ton-scale program, which includes a major upgrade to the detector described in the next section.

Ton-Scale ExperimentsIn order to make a definitive search for 0νββ in the in-

verted mass-hierarchy, target masses on the order of a few tons are required. Several collaborations are developing de-tector concepts to probe this parameter space. KamLAND2-Zen and nEXO propose to search for 0νββ in 136Xe deploy-ing 1 ton and 5 tons of enriched Xe, respectively. Their projected sensitivity limit is show as a cross-hatched band in Figure 1.

nEXO The nEXO detector concept is based on the success of

EXO-200. The detector is anticipated to be deployed at SNOLAB in Ontario, Canada, where the Nobel Prize–win-ning SNO detector was located. An artist rendering of the detector is shown in Figure 4. nEXO is being designed as a cylindrical, monolithic, single-volume, liquid xenon TPC with a drift field of 400 V/cm deploying 5 tons of xenon en-riched in 136Xe at ~90%. A segmented anode with perpen-dicular x and y channels collects the charge signal, while

Figure 3. (left) KamLAND-Zen Energy spectrum of selected 0νββ candidates within a 1-m-radius spherical volume in Period-2 drawn together with best-fit backgrounds, the 2νββ decay spectrum, and the 90% C.L. upper limit for 0νββ decay from Ref. [8]. (right) Schematic diagram of the KamLAND-Zen detector from Ref. [9].

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scintillation light is recorded by Silicon Photon Multipli-ers (SiPMs). These photon detectors are mounted outside of the field shaping rings, but inside the liquid xenon vol-ume, covering the area of the cylindrical detector wall (~4 m2 area). SiPM devices sensitive to Xe-scintillation light at 175 nm are currently being developed and tested by the nEXO collaboration [10].

Simulations of nEXO, based on EXO-200 and radio-assay data, predict a sensitivity to T1/2

0ν of 9.4 · 1027 years after 10 years of data taking. The resulting sensitivity to the effective Majorana neutrino mass is shown as a cross-hatched band in Figure 1 for different matrix elements [3, 4]. This assumes an improved energy resolution of 1% at the Q-value, which is achieved by improved light detec-tion and electronics. nEXO, like EXO-200, will fully re-construct event energy, location, multiplicity, and topology. This sophisticated reconstruction in conjunction with the self-shielding of xenon will significantly increase nEXO’s sensitivity in comparison to an experiment deploying a sim-ilar target mass of a different isotope in many small-volume detectors.

KamLAND2-ZenKamLAND2-Zen’s focus is an improvement in the en-

ergy resolution from ~4% √E to ~2% √E. The detector has been running continuously for more than 15 years and is due for a major refurbishment. As part of this work the de-tector will be drained and the main spherical tank will be inspected. The improvement in energy resolution comes from the installation of new high quantum efficiency pho-tomultiplier tubes with Winston cones and a higher light yield LAB-based liquid scintillator. The R&D indicates

that these three improvements boost the light collection ef-ficiency by factors of 1.9, 1.8, and 1.4, respectively.

The improvement in energy resolution is complemented by a modest increase in the isotope mass to bring the total to 1 ton and new electronics to improve the tagging of the muon spallation background from 10C. More novel back-ground techniques involving scintillating balloon film and a secondary imaging system are also being explored. The goal of the KamLAND2-Zen phase is to reach 20 meV.

Beyond the Ton-ScaleThe increase in sensitivity in future 0νββ searches will

be limited by the available target mass. Advanced technolo-gies may provide a path forward toward probing further into the normal neutrino-mass hierarchy. These technologies must suppress β, γ and even solar neutrino backgrounds that ultimately limit a detector’s sensitivity to 0νββ.

Two approaches are presented with the potential to iden-tify ββ events by either probing the decay volume for the existence of the 136Xe decay daughter 136Ba, or by applying directionally sensitive liquid scintillator.

Barium Tagging for 0νββ SearchesBa-tagging is being developed for application in a

monolithic xenon TPC and describes the following con-cept: when a 0νββ-candidate event is recorded, it is local-ized instantly and a small volume surrounding the event’s location is extracted from the detector volume and probed for the presence of a Ba-ion. If a 136Ba is found, the event is considered for the 0νββ search, otherwise it is classified as background. This unambiguous identification of events at the Q-value as ββ or background events increases the detector’s sensitivity without increasing its mass, however, more significant is the ability to confirm an observed 0νββ signal as originating from true ββ-decay events.

Ba-tagging has been proposed by Ref. [11] and various approaches are pursued by the nEXO collaboration using a tip or cold probe to extract 136Ba from the volume [12, 13] (see Ref. [14] for a proposed technique to identify Ba inside the detector). An alternative approach proposes to move a capillary close to the event location and flush the 136Ba-ion out of the detector with liquid xenon. Once outside the detector, the xenon undergoes a phase transition and a radio-frequency (RF) ion funnel is applied to separate ions from the neutral xenon gas. Following the extraction into vacuum, the Ba-ion will be captured in a linear Paul trap and identified through isotope-selective laser-fluorescence spectroscopy. Such a system is currently being developed collaboratively by Carleton University, McGill University, and TRIUMF and is based on an RF ion funnel developed

Figure 4. Artist rendering of the nEXO TPC (right) and its installation at the SNOLAB cryopit (left). The cryostat is submerged in a water tank, which acts as active shield-ing. SiPMs will be mounted between field shaping rings and detector wall.

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at Stanford University. This RF-funnel allowed the extrac-tion of ions, produced by either a 148Gd α or a 252Cf fission source, from xenon gas of up to 10 bar into vacuum [15], achieving for the first time ion extraction from such high pressures. In parallel, an element-sensitive fluorescent laser spectroscopy technique on Ba-ions trapped in a linear Paul trap has been developed and individual trapped Ba-ions were identified [16]. The RF-funnel ion-extraction and flu-orescent laser spectroscopy setup will be further improved and combined to demonstrate the feasibility of the proposed approach. For future studies, the radioactive ion source will be replaced with a surface laser-ablation ion source to selec-tively create Ba ions for extraction studies. A schematic of the proposed setup is shown in Figure 5. A multi-reflection time-of-flight mass spectrometer will be added to allow for identification of ions other than barium, which is of interest for ion-extraction and ion-transport studies.

Significant progress has been made in the development of Ba-tagging techniques; Ba-ion identification through laser-fluorescence spectroscopy especially has achieved a sensitivity on the one to three ion level. Further efforts will focus on implementing this development in a workable Ba tagging technique, which is sensitive to individual ions in tons of xenon. Ba-tagging is a great challenge, however, the significant increase in sensitivity to T1/2

0ν and the possibil-ity to identify events as true ββ decays makes it a powerful tool that can be applied to a future nEXO-like detector.

Directional Liquid ScintillatorThe next step in the KamLAND program is Super-Kam-

LAND-Zen with a target sensitivity of 8 meV. The increased

sensitivity comes from installing 40 tons of pressurized xenon-doped liquid scintillator into the center of Super-Ka-miokande. This would be coordinated with the start of Hy-per-Kamiokande. The pressurization is needed to increase the xenon concentration in the mini-balloon. This allows an increase in mass while maintaining background levels since most backgrounds scale with volume. The R&D has already begun both on the light yield of this pressurized xenon scin-tillator and on the engineering of this balloon.

At this size and target sensitivity, the background from 8B solar neutrinos is non-negligible. The ability to recon-struct the direction of the ~MeV electrons would be a pow-erful background rejection tool for both this and other back-grounds and would be revolutionary for large-scale liquid scintillator detectors in general.

Direction reconstruction relies on the ability to sepa-rate the Cherenkov and scintillation light. The composition of a liquid scintillator cocktail determines an absorption cutoff, photons with wavelengths shorter than this wave-length become part of the isotropic scintillation light, but photons with wavelengths longer than this cutoff propagate undisturbed and retain their directional information. Ref. [17] showed that this separation could be obtained and the direction of ~MeV electrons could be reconstructed if photo detectors with ~100 ps timing were used, see Fig-ure 6. The separation is improved with red-sensitive photo cathodes and scintillator emission spectra narrowed using novel wavelength shifters like quantum-dots. The CHESS experiment recently demonstrated Cherenkov/Scintillation separation in an LAB-based cocktail using a bench-top ap-paratus and cosmic muons [18]. A prototype detector called

Figure 5. Schematic of the setup to extract Ba-ions from xenon gas and identify them by means of laser-fluorescence spec-troscopy. Ba-ions are produced through laser-ablation at a source target located in xenon gas and extracted into vacuum by a combination of RF funnels. The mass spectrometer is proposed for systematic ion-extraction studies. Gas-flow calcu-lation courtesy of V. Varentsov.

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NuDot is being constructed at MIT to demonstrate this technique on the ton-scale.

ConclusionThe search for 0νββ decays is an exciting quest to inves-

tigate if neutrinos are Majorana particles. Current genera-tion experiments, such as KamLAND-ZEN and EXO-200, are probing the degenerate hierarchy parameter space down to about 60 meV. With the advent of ton-scale experiments, this limit will be pushed below 10 meV, hence fully prob-ing the inverted mass hierarchy. Depending on the nature of the neutrino, a ground-breaking discovery is within reach of next generation 0νββ detectors. It is an exciting time for 0νββ decay searches.

AcknowledgmentsT. B. and L. W. acknowledge support from the EXO-

200 & nEXO, and KamLAND-ZEN collaborations, respec-tively.

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5. J. B. Albert et al., Nature 510 (2014) 229. 6. J. B. Albert et al., Phys. Rev. C 89 (2014) 015502. 7. M. Auger et al., Journal of Instrumentation 7 (2012) P05010. 8. A. Gando et al., Phys. Rev. Lett. 117 (2016) 082503. [Adden-

dum: Phys. Rev. Lett. 117 (2016) 109903]. 9. A. Gando et al., Phys. Rev. C85 (2012) 045504.10. I. Ostrovskiy et al., IEEE Trans. Nucl. Sci. 62 (2015) 1825.11. M. K. Moe, Phys. Rev. C 44 (1991) R931.12. K. Twelker et al., Rev. Sci. Instr. 85 (2014) 9.13. B. Mong et al., Phys. Rev. A 91 (2015) 022505.14. B. Jones, A. McDonald, and D. Nygren, Journal of Instru-

mentation 11 (2016) P12011.15. T. Brunner et al., Inter. J. Mass Spectr. 379 (2015) 110.16. M. Green et al., Phys. Rev. A 76 (2007) 023404.17. C. Aberle et al., JINST 9 (2014) P06012.18. J. Caravaca et al., (2016) arXiv:1610.02011v1.19. J. B. Albert et al., (2017) arXiv:1707.08707.

Figure 6. (left) Photoelectron (PE) arrival times after application for the simulation of 1,000 electrons (5 MeV). PEs from Cherenkov light (black, solid line) and scintillation light (red, dotted line) are compared. The dash-dotted vertical line il-lustrates a time cut at 34.0 ns. This is the default simulation: bialkali photocathode and TTS = 0.1 ns (σ). After the 34.0 ns time cut, 171 PEs from scintillation and 108 PEs from Cherenkov light are detected. (right) The reconstructed direction, (px/|p| ,py/|p| ,pz/|p|), for the simulation of 1,000 electrons. In the simulation, the electrons are produced along the x-axis, p/|p| = (1,0,0), and originate at the center of the 6.5 m-radius detector, r = (0,0,0). Only photons with arrival time of t < 34.0 ns are used in the reconstruction. The quantum efficiency of the bialkali photocathode is taken into account. The reconstruction at 1.4 MeV is shown. From Ref. [17].

|p/|x,y,zp-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

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ts /

0.05

0

20

40

60

80

100

120

140

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180

)θ = cos(|p|xp

|p|yp

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Time [ns]30 35 40 45 50

PEs

per

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0

10

20

30

40

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Photon Arrival Time Reconstructed Direction

Early Cherenkov Light

Scintillation Light

L. WinsLoWT. Brunner

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20 Nuclear Physics News, Vol. 27, No. 3, 2017

IntroductionAccelerator Mass Spectrometry

(AMS) is a technique to measure long-lived radioisotopes with very high sensitivity. The radioisotopes can be of natural origin such as cos-mogenic nuclides produced by cosmic rays or of anthropogenic origin such as nuclides produced in nuclear fuel processing or nuclear weapons tests. Since its development in 1977 AMS has revolutionized the field of radio-nuclide dating. There is nowadays a wide range of applications for AMS in various fields like earth and ocean sciences, archaeology, hydrology, pollution studies, biochemistry, and biomedicine [1]. Throughout the last years, AMS enabled investigations of various astrophysical processes. The detection of supernova-produced 60Fe in manganese crusts [2], deep-sea res-ervoirs [3, 4], and microfossils [5, 6] as well as on the surface of the moon [7] constrained a near-by supernovae events approximately 2 million years ago. Moreover, the high sensitivity of the AMS measurements might indi-cate multiple supernovae events in the near-earth region (<100 parsec) from 3 million to 2 million years ago [4].

Due to the increasing demand for AMS measurements using cosmo-genic nuclides, for example, 10Be, 14C, 26Al, 36Cl, 41Ca the German Research Foundation (DFG) decided in 2007 to fund a new 6 MV high performance AMS user facility. After a competition process between German universities and research centers, it was decided to install the device at the Institute for Nuclear Physics of the University of Cologne. Together with two sample preparation laboratories, operated by the Institute of Geology and Miner-

alogy of the University of Cologne it constitutes a new center for Accel-erator Mass Spectrometry at the Uni-versity of Cologne called “Cologne AMS” [8]. The main local research program is focused on applications in the geosciences. Examples are expo-sure dating of glacial moraines impor-tant for global climate change studies, the investigation of fault movements for tectonics and paleoseismics, and the quantification of landscape evolu-tion. The Institute for Nuclear Physics adds a research program in Nuclear Astrophysics, for example, search for 60Fe and 244Pu in lake sediment cores and more precise measurements of half-lives of radionuclides with cru-cial impact on astrophysical models.

The AMS Device at the University of Cologne and the Actual Performance

The layout of the actual AMS system is shown in Figure 1. It was built by High Voltage Engineering, Amersfoort, the Netherlands [9]. The injector consists of a low energy mass spectrometer with a 54° electrostatic analyzer (ESA) and a 90° dipole mag-net with a bending radius ρ = 45 cm. The injector is equipped with a multi sample negative ion sputter source that can be loaded with up to 200 sample cathodes. The ESA of the in-jector can be mechanically switched from +54° to −54° which allows to mount two ion sources in parallel. Ac-tually, the second ion source mounted at −54° is used solely for CO2 mea-surements. The accelerator, a 6 MV TANDETRON, uses a parallel fed Cockcroft-Walton generator as a charging system equipped with an all-

solid-state high voltage power supply. This results in a low ripple and high stability of the terminal voltage with-out the need of a corona-stabilization. The accelerator can be operated with foil and gas stripper. Because of the absence of moving parts, except of a rotating shaft driving a generator in the terminal, dust production is rather low which results in very low down time of the machine. It is followed by the high-energy mass spectrometer. It consists of a 90° high mass resolving analyzing magnet (ρ = 2 m) and two 35° electrostatic deflectors before the ions are directed into the particle de-tectors for the rare isotope counting. Since in AMS normally isotopic ra-tios are measured, the stable isotopes need to be measured too. This is done in Faraday cups directly after the 90° analyzer magnet. It has to be ensured that the ion optical conditions for the rare and stable isotopes are identical. This is realized by putting the cham-ber of the low energy 90° magnet on a high voltage potential via a fast high voltage bouncer power supply to ad-just the momentum of the stable iso-bars to that of the radioactive isotope. The sequential injection of the differ-ent beam components is repeated at a frequency of 100 Hz.

A switching magnet with ports at −/+30°, −/+15°and 0° positioned downstream of the ESA allows to use different detector setups. The one at −30° is used for 14C and 26Al for which no stable isobar suppression is needed. At +30° a degrader foil is followed by a high acceptance 120° magnet, which reduces isobaric beam components entering the ionization chamber. For more details see Refs. [8, 9].

The Actual AMS Capabilities at the University of Cologne

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Performance and ImprovementsCologneAMS started its opera-

tion in 2011 and since then the num-ber of measured samples increases steadily. Actually about 2,500 samples are measured per year. The precision reached (Table 1) is at highest level worldwide. Scientific projects where CologneAMS contributes with AMS measurements are related to the DFG

Collaborative Research Centre 806, speaker A. Richter: “Our Way to Eu-rope, Culture-Environment Interac-tion and Human Mobility in the Late Quaternary.” In 2016 a new Collabor-ative Research Centre 1211, speaker T. Dunai: “Earth—Evolution at the Dry Limit” was approved. This CRC in-cludes a dedicated project for techno-logical and methodical developments

in the field of AMS including new techniques and detectors, ion sources, and overall instrument design as well as the development of new nuclide systematics. For investigating short-term geological processes and for very long-term processes measurements of 41Ca and 53Mn are used, respectively. The isotope 32Si is suited as a potential tracer for ocean circulations.

Figure 1. Layout of the actual 6 MV TANDETRON AMS setup. Also shown are photos depicting parts of the installation (for more details see text).

Precision of Terminal Current at LE-cup/ modern isotope voltage/charge transmission Reproducibility Blank ratio (for highRadionuclide state LE- to ANA-cup of standards values counting statistics)14C 5.5 MV/4+ 40–50 µA (elect.)/50% 0.4% 1∙10–16 0.4%14CO2 5.5 MV/4+ 7–12 µA (elect.)/50% 0.8% 9∙10–15 5 µg—2.5% 30 µg—1%10Be(1) 4.5 MV/2+ 2 µA (elect.)/60% 1% 1∙10–16 3%26Al(2) 3 MV/3+ 200 nA (elect.)/36% 1% 5∙10–16 3%36Cl(3) 6 MV/5+ 25 µA (elect.)/27% 1% 5∙10–15 3%

Pu(4) 3 MV/3+ — 1% — 3%(1)Degrader foil technique with 120°-magnet (for 4+ charge state); ion extracted from source: BeO–; (2)no interferences; (3)degrader foil technique with

120°-magnet (for 10+ charge state); (4)slow sequential injection; ion extracted from source: PuO.–

Table 1. Details on the actual AMS performance at CologneAMS for different isotopes.

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22 Nuclear Physics News, Vol. 27, No. 3, 2017

In addition to the routine measure-ments several new developments were made to increase the measurement capabilities and to improve the perfor-mance for specific isotopes. First the original system was enlarged by add-ing a specific detector for actinides (U, Pu) and a time of flight (TOF) detec-tion system. The second ion source is dedicated for CO2 samples (financed partly by the GFZ Potsdam within the frame of a common collaboration). It was installed in 2015 and since then optimized for high output of nega-tive carbon ion beams [10]. Negative carbon ions can be extracted from the ion source with an efficiency of 5%. Small samples down to 3 µg can be measured. This enables in-situ and compound specific 14C measurements. Both techniques are employed by ge-ologists who use compound specific 14C AMS measurements to investigate biodegradation in thawing permafrost soils studies with the aim to estimate the amount of C02 or CH4 release of thawing permafrost regions [11].

Soil Erosion Studies with Pu Originating from Bomb Test Fallout

Aside from cosmogenic nuclides actinides can be efficiently measured at the Cologne AMS facility. The first AMS measurement of this type used 239,240,242Pu isotopes in a study of soil erosion from sites in South Africa. The identification of the Pu origin for soil samples from the farmlands of South Africa was determined via the 240Pu/239Pu-ratios measured in soil samples. The acquired 240Pu/239Pu-ratios of these samples resulted in a mean value of 0.181 ± 0.001, which agrees with the adopted value of 0.180 for the global plutonium fallout [12]. These samples were then used to in-vestigate the soil erosion related to agricultural activities. The absolute Pu concentration was determined by

using a known 242Pu spike material. Figure 2 shows the plutonium activity of the examined farmland, calculated from the sum of the absolute concen-trations of 240Pu and 239Pu content, as a function of the years of cultivation. The graph shows the expected behav-ior caused by soil erosion. A dramatic fertile soil loss (>50%) is observed within the first 10 years of cultivation activities [13].

A New AMS Setup at the 10 MV FN Tandem Accelerator

This setup aims for AMS appli-cations with medium mass isotopes where isobar suppression benefits from high beam energies (e.g., 32Si, 41Ca, 60Fe or 53Mn) [14]. Figure 3 shows the new setup as it will be realized in its final stage. It consists of a low energy mass spectrometer with a multi-athode sputter ion source (NEC) followed by a 90° electrostatic deflector and 90° bending magnet with a bending radius ρ = 45 cm. The injector is equipped for fast sequencing injections of rare and stable isotopes. The high energy mass spectrometer that follows the 10

MV Tandem accelerator consists of a double focusing 90° dipole magnet (ρ = 100 cm) followed by a multi- faraday cup unit where the stable iso-topes are measured. Further down-stream a 30° electrostatic deflector (ρ = 300 cm) is positioned with a degrader foil in front, which can be inserted into the beam. Further mass separation can be achieved by a second degrader foil in combination with a TOF system. The rare isotopes will be registered in a multi-anode ionization chamber. Very soon this setup will be equipped with a 135° gas filled magnet (ρ = 100 cm). This magnet will be used especially for the measurement of 53Mn where it is crucial to suppress effectively the stable isobar 53Cr.

SummaryIn 2011 a new center for AMS

(CologneAMS) became operational at the University of Cologne. Since then more than 10 000 routine mea-surements have been performed. New developments enlarged significantly AMS’ capabilities; for example, the new 14CO2 injector enables the mea-

Cultivation time [a]

Figure 2. 239+240Pu activity determined from the absolute concentration of the measured 239Pu and 240Pu concentrations in soil samples of farmland in Tweespruit (South Africa) as a function of cultivation time. Shown are the experi-mental values measured independently at CologneAMS and Australian National University (ANU) as well as a line to guide the eye.

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Vol. 27, No. 3, 2017, Nuclear Physics News 23

surement of very small samples (down to 3 µg of carbon). It has been dem-onstrated that actinides can also be measured with high accuracy and sen-sitivity using a new ionization cham-ber. Currently, a new AMS setup at the 10MV FN Tandem accelerator is be-ing installed that is dedicated for me-dium mass isotopes. It will be finished in 2017. This setup will provide the opportunity to perform 60Fe and 53Mn AMS measurements that will be used in astrophysical as well as in geosci-ence projects.

AcknowledgmentsThis work was supported by the

German Research Foundation (DFG) under Contract No. ME1169/19-1, and partly by the University of Cologne in the frame of the excellence iniciative “Emerging Groups,” ULDETIS, and

by the German Geo Research Centre (GFZ) Potsdam.

References 1. C. Tuniz, W. Kutschera, and D. Fink,

Accelerator Mass Spectrometry (CRC Press, Boca Raton, FL, 2009).

2. K. Knie et al., Phys. Rev. Lett., 93 (2004) 17.

3. C. Fitoussi et al., Phys. Rev. Lett. 101 (2008) 121101.

4. A. Wallner et al., Nature 532 (2016) 69.

5. P. Ludwig et al., PhD thesis, TU Mu-nich (2015).

6. S. Bishop and R. Egli, Icarus 212 (2011) 960.

7. L. Fimiani et al., Lunar Planet. Sci. Conf. 45 (2014) 1778.

8. A. Dewald et al., EPJ Web of Confer-ences 63 (2013) 03006.

9. M. G. Klein et al., Proceedings of the Conference: ECAART-10, Athens (2010).

10. A. Stolz et al., Proceedings of the Conference: ECCART-12 (2016), ac-cepted.

11. A. Wotte et al., Nucl. Instr. Meth. Phys. Res. B, submitted.

12. Ken O. Buesseler, J. Environ. Radio-act. 36 (1997) 69.

13. H. Wiesel, PhD Thesis, University of Cologne (2013).

14. M. Schiffer et al., Proceedings of the Conference: ECCART-12 (2016), ac-cepted.

Alfred dewAld

Institute for Nuclear Physics, University of Cologne

Figure 3. Layout of the AMS setup at the 10 MV FN accelerator dedicated for medium mass spectroscopy. Also included are photos showing parts of the installation.

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24 Nuclear Physics News, Vol. 27, No. 3, 2017

The Antiproton Anihilation in Darmstadt (PANDA) collaboration at the Facility for Antiproton and Ion Re-search (FAIR) is a cooperation of more than 400 scientists from 19 countries.

FAIR will be an accelerator facil-ity leading the European research in nuclear and hadron physics in the coming decade. It will address a wide range of physics topics in the fi elds of nuclear structure, nuclear matter, atomic, and plasma physics. Several topics in applied science and accelera-tor development will be addressed as well. FAIR builds on the experience and technological developments from the existing GSI facility, and incor-porates new technological concepts, such as rapidly cycling super-conduct-ing magnets.

The existing GSI accelerators will be upgraded and complemented by a proton-linac to be used as injectors for the newly built complex of synchro-trons and storage rings to form FAIR. This facility will provide intense sec-ondary beams of antiprotons and rare isotopes, which will be used for the research at the experimental setups.

It is sometimes said that the whole is more than the sum of its parts. For the proton, this expression is literally true. The sum of the masses of its va-lence quarks account for less than 2% of the proton’s total mass, with the rest resulting from the kinetic and binding energies among quarks due to dynam-ics of the strong interaction. The ac-cepted theory of the strong interaction is quantum chromodynamics (QCD). It describes the properties of quarks and their interactions through glu-ons, the force mediator of the strong interaction. QCD is very successful in predicting processes at high ener-

gies where the coupling constant αs is small and perturbation theory is appli-cable. However, at low energies, the theory becomes strongly coupled as αs becomes large. In this non-pertur-bative regime, it is still hard to make predictions from fi rst principles. Fur-thermore, complex systems of quarks and gluons are strongly coupled many-body problems.

The complexity of many-body sys-tems in non-perturbative QCD gives rise to many questions: What are the effective degrees of freedom that sys-tematically describe resonances and bound states? Where are the exotic resonances and bound states predicted by QCD? How do bound quark sys-tems interact? What is the residual structure of the hadronic systems? Thus, the central goal of the PANDA experiment is the elementary under-standing of hadrons using the power of an antiproton beam on hydrogen or nuclear targets.

The annihilation of antiprotons has proven in the past to be a universal tool for carrying out such investiga-

tions. Open and hidden charm, lepton pairs and radiative channels, hidden strangeness and hyperons, are com-mensurable probes to explore the im-minent questions among bound states of QCD.

“Why antiprotons?” is asked fre-quently. The answer lies in the advan-tages antiprotons have in the produc-tion of a rich variety of hadrons with respect to other experimental probes and the fl avor-blindness of the well-defi ned initial states, which is comple-mented by the unique feature of high precision mass scanning.

An important feature of the new an-tiproton facility is the combination of phase-space cooled beams and dense internal targets, comprising challeng-ing beam parameters in two operation modes: a high-luminosity mode with beam intensities up to 1011 in a later stage, and a high-resolution mode with a momentum spread down to a few times 10−5 and beam intensities up to 1010. A powerful stochastic cooling system will be employed to meet the experimental requirements. The High

PANDA: Strong Interaction Studies with Antiprotons

Figure 1. High Energy Storage Ring at FAIR. The PANDA detector is located in one of the straight sections where the antiproton beam interacts with a fi xed target.

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Energy Storage Ring (HESR) is fi lled by the Collector Ring (CR), which ac-cumulates by stacking the antiprotons every 10 seconds from the collision of 2.5 × 1013 protons of 29 GeV in a 50 ns bunch on the production target.

The HESR lattice is designed as a racetrack-shaped ring, consisting of two 180° arc sections connected by two long straight sections. One straight section will mainly be occu-pied by an electron cooler at a later stage and will host smaller experi-ments for nuclear and atomic physics with ion beams. The other section will host RF cavities, injection kickers, septa (Figure 1), and the installation of the PANDA experiment with an internal target. For stochastic cooling, pickup and kicker tanks are located in the straight sections, opposite to each other. The momentum of the antipro-tons ranges from 1.5 to 15 GeV/c, al-lowing for a wide variety of physics channels (Figure 2).

The PANDA experiment belongs to the third generation of hadron physics experiments, hereby building on the

experiences and successes of previous generations.

The availability of accelerators and detectors like the bubble chambers led to a prosperous time in particle phys-ics in the 1950s and 1960s with the discovery of many new particles. The vast majority of these particles came to be understood, at least qualitatively,

due to the pioneering work of Gell-Mann as being composed of quarks that interact with each other via the exchange of gluons. Baryons are had-rons consisting of three quarks, and mesons are hadrons consisting of an antiquark–quark pair.

The fi eld of hadron physics was fragmented over decades, according to the questions under investigation and subject to the methods and tools used, into the branches of spectroscopy, structure, and interactions of hadrons.

While specialized experiments have been dedicated to each of those subfi elds over the past 20 years, the PANDA experiment has been espe-cially designed together with the ac-celerator to address open and burning questions from all the subfi elds and beyond.

The PANDA experiment features a modern multipurpose detector (Figure 3). The combination of a high-quality antiproton beam at the HESR, an un-precedented annihilation rate, and a sophisticated event fi ltering, is an ideal experimental infrastructure to address important questions to all aspects of this fi eld by collecting large statistics and high-quality exclusive data to test

Figure 2. Some of the many accessible hadron species with PANDA and HESR.

Figure 3. CAD drawing of the PANDA detector, currently under construction and to be completed and commissioned in 2024.

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26 Nuclear Physics News, Vol. 27, No. 3, 2017

QCD in the non-perturbative regime. In the following, we will outline a few of the physics aspects that will be ad-dressed using this facility (see Refs. [1, 2] for more details).

PANDA will copiously produce an-tihyperon–hyperon pairs through the reaction pp → YY. The energy scale is given by the mass of the strange quark (ms ~ 100 MeV/c2), which is below, but near the strong coupling scale ΛQCD. This corresponds to the confinement domain, where our knowledge of the strong interaction is scarce. Therefore, the relevant de-grees of freedom—quarks and gluons or hadrons—remain unclear. Spin ob-servables have been proven to be very sensitive to the underlying degrees of freedom of the model describing the interaction. The high cross-section for hyperon pair production using anti-proton interactions (see Figure 4) will provide the necessary high statistics to access spin observables with sufficient precision. In addition, so far unmea-sured multi-strange hyperons are ac-cessible with PANDA. In particular, seven polarization parameters of the spin 3/2 Ω hyperon can be extracted for the first time.

This large production cross-section will also enable several innovative studies of systems containing two or even more units of (anti)strangeness in antiproton–nucleus collisions at the PANDA experiment. The interaction

of antibaryons in nuclei provides a unique opportunity to elucidate strong in-medium effects in baryonic sys-tems. Quantitative information on the antihyperon potentials will be obtained for the first time via exclusive antihy-peron–hyperon pair production close to its production threshold in antiproton–nucleus interactions. After pioneering studies of the Λ potential during the first phase of PANDA, the Ξ and even the Ω potential can be explored once the full luminosity is available. Bary-ons with strangeness embedded in the nuclear environment, hypernuclei, or hyperatoms, are the only available tool to approach the many-body as-pect of the three-flavor strong interac-tion. As an example, high resolution γ-spectroscopy of excited states in sev-eral doubly strange ΛΛ-hypernuclei will be performed for the first time. Hypernuclear studies would result also in valuable insights to astrophysics as well, such as the Hyperon-puzzle of neutron stars and mechanisms of core-collapse supernovae.

The field of charmonium spectros-copy is an exciting field with many discoveries in the past 15 years. Many predicted states have not been ob-served and, on the other hand, masses, widths, and decay rates of many unex-pected states (XYZ states) have been measured. Until today, a coherent picture cannot be drawn from what is available experimentally. PANDA will

contribute to this field in two unique ways: (a) in explorative studies in many-body experiments to search for high-spin and spin-exotic states and (b) by a precision measurement of the mass and width (or more generally the line-shapes) of any neutral charmo-nium-like state. The very small mo-mentum spread of the antiproton beam allows a determination of the width, for example of the X(3872), with an accuracy of 50 keV. Such an accuracy will provide a decisive measurement on the nature of the narrow X(3872). This technique can also be used to investigate excitation curves of open-charm final states, like, for example, DsDs0*(2317) to measure the width of the respective Ds0*(2317).

Furthermore, antiproton annihila-tions allow for the study of a rich va-riety of nucleon structure observables in large (partly) unexplored areas such as the kinematical regime that cor-responds to the time-like (positive, s-channel) momentum transfer of the virtual photon. The electromagnetic form factors of the proton, transition distribution amplitudes (TDA), wide angle compton scattering (WACS), and Drell-Yan processes for access-ing transition momentum-dependent parton-distribution functions (TMD-PDF) are examples of those variables. Figure 5 shows how crossing symme-try, for example, connects space- and time-like regions.

The main objectives of the design of the PANDA experiment are to achieve almost 4π acceptance, high resolution for tracking, particle identification and calorimetry, high-rate capabilities, and a versatile readout and event selection. To obtain a good momentum resolu-tion, the detector will be composed of two magnetic spectrometers: the Target Spectrometer (TS), based on a superconducting solenoid magnet surrounding the interaction point, for particle tracks at large angles and the

0.01

0.1

1

10

100

1000

1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2 4 6 8 10 12 14

σ[µb]

pp→ ΛΛ

→ ΛΣ0 + c.c.

→ Σ− Σ+

→ Σ0Σ0

→ Σ+ Σ−

→ Ξ0Ξ0

→ Ξ+Ξ−

ΛcΛcΞΞ ΩΩΛΣ0 ΣΣΛΛ

p momentum [GeV/c]Figure 4. High antihyperon–hyperon production cross-sections in antiproton–proton annihilations.

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Forward Spectrometer (FS), based on a dipole magnet, for small angle tracks. In both spectrometer parts, tracking, charged-particle identifi ca-tion, electromagnetic calorimetry, and muon identifi cation will be available to allow detection of the complete spectrum of fi nal states relevant for the PANDA physics objectives.

The TS has a typical onion-like structure, very much like the detec-tors used for the B-Factories Babar and Belle: A cluster jet or pellet target system will be used to provide either a cluster beam of a target gas or frozen hydrogen pellets. Thin foils or noble gasses will be used for antiproton-nucleus studies. The interaction point is surrounded by the Micro Vertex De-tector (MVD) which has a vertex res-olution of about 50 μm in transverse and 100 μm along the beam direction. Surrounding the MVD, the Straw Tube Tracker and Gas Electron Multiplier (GEM) stations will be used for track-ing charged particles (∆pT/pT = 1.2%) in the magnetic fi eld. Photons and the energy of electrons will be re-constructed with the Electromagnetic Calorimeter (EMC). The EMC con-sists of a barrel (azimuthal angle 22° to 140°), a forward endcap (down to the opening for the FS) and backward

endcap (145° to 170°) and consists of about 16,000 PbWO4 crystals provid-ing an energy resolution of 1.5%/√E, whereby E is given in units of GeV. Particle identifi cation of pions, kaons, and protons will utilize information from a time-of-fl ight system (ToF), a cylindrical Detection of Internally Re-fl ected Cherenkov (DIRC) light, and a forward Disc DIRC detector. The ToF will use scintillating tiles with Silicon Photomultiplier readout. The cylin-drical DIRC is a bar-type DIRC with quartz-prisms, while the Disc DIRC uses large quartz plates. The solenoid magnet will provide a homogeneous magnetic fi eld up to 2 T in the beam direction. The segmented yoke is in-strumented with chambers for muon identifi cation.

The FS covers polar angles below 10° horizontally and 5° vertically. Charged particles will be detected using the Forward Tracking System, which consists of multiple straw tube layers, in conjunction with a dipole magnet with variable fi eld depending on the incident antiproton momentum. The momentum resolution for tracks above 1 GeV/c is better than 1%. A Forward ToF and an aerogel-based Ring Imaging Cherenkov Counter detector will provide particle identi-

fi cation. A Shashlyk-type calorimeter with an energy resolution of 3%/√E is followed by the Muon Range System for muon detection. At the forward end, the Luminosity Detector uses elastic scattering of antiprotons on protons to determine the interaction rate measuring antiprotons defl ected at low angles. A detailed description of the PANDA detector and its com-ponents can be found at Ref. [4].

As the detector response of back-ground events is very similar to that of the decay of the exotic states, the use of a conventional triggered readout scheme, where a limited number of subdetectors generates a trigger signal that engages the readout of the com-plete detector, is not practical. There-fore, a new type of intelligent readout is being developed, where kinematical constraints are imposed online on re-constructed events. This technique is dubbed as “triggerless readout” and allows adjusting the data selection to numerous physics channels. A data reduction factor of up to ~103 is ex-pected to be achieved by employing this technique for the whole detector, resulting in a data rate of ~104 events/s (or, equivalently, 200 MB/s) that will then be sent to storage for offl ine pro-cessing and analysis.

Figure 5. Crossing symmetry relates electromagnetic scattering off the proton to, for example, lepton and photon pair production from antiproton–proton annihilations (elm FF = electromagnetic form-factor, GPD = generalized parton dis-tribution, GDA = generalized distribution amplitudes, Mh = hard process amplitude, DA = distribution amplitude, see Refs. [1, 3] for more details).

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28 Nuclear Physics News, Vol. 27, No. 3, 2017

Besides the foreseen advances in detector technology and data treat-ment, also the theoretical develop-ments that go hand-in-hand with the experimental developments will lead to new and deep insights into the dy-namics of the strong interaction. The insights that PANDA will gain in the fi eld of QCD might have far-reaching implications to other fi elds of physics as well, in particular for those in which similar non-perturbative phenomena take place (wide range reaching from string theory to weather phenomena). The study of non-perturbative phe-nomena in a systematic way is feasible only in hadron physics. This supple-ments the long list of features that can be addressed with PANDA.

GSI has a distinguished history of having made important contributions to the physics of the strong interac-tion, in particular in the fi eld nuclear physics. FAIR will be built on these foundations and the proposed PANDA experiment plays a complementary role, providing a link between nuclear and hadron physics. The construction of the PANDA detector has started and in-situ commissioning of the ini-tial setup is scheduled for 2024, while early physics with an antiproton beam is expected in 2025.

References1. M. F. M. Lutz et al., Physics Perfor-

mance Report for PANDA: Strong Interaction Studies with Antiprotons, arXiv:0903.3905 (2009).

2. M. F. M. Lutz et al., Nucl. Phys. A948 (2016) 93. https://doi.org/10.1016/j.nuclphysa.2016.01.070

3. U. Wiedner, Prog. Part. Nucl. Phys. 66 (2011) 477. doi:10.1016/j.ppnp.2011.04.001

4. https://panda.gsi.de

KLAUS PETERS

GSI Darmstadt;Goe the University Frankfurt

LARS SCHMITT

FAIR

TOBIAS STOCKMANNS

FZ Jülich

JOHAN MESSCHENDORP

KVI-CART Groningen

D o y o u k n o w ?

Authors may now choose to publish their articles with Taylor & Francis Open Select.

http://journalauthors.tandf.co.uk/preparation/OpenAccess.asp

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Vol. 27, No. 3, 2017, Nuclear Physics News 29

IntroductionWith Accelerator Mass Spectrom-

etry (AMS) ultra-low isotopic abun-dances (10–12 to 10–16) of long-lived radionuclides, both natural and an-thropogenic, are being measured by including an accelerator. Direct atom counting results in an enormous gain in detection sensitivity for long-lived radionuclides as compared to their rare decay. For the most-used radio-nuclide, 14C (half-life = 5,700 yr), this means that instead of grams of carbon required for beta counting one can use milligrams or even micrograms to de-termine the 14C content. In addition, an AMS measurement takes less than an hour rather than the several days re-quired for beta counting. The gain be-comes even larger for longer half-lives in the million-year range and beyond.

Multiple filtering is the chief task of AMS in order to identify and count very rare radionuclides in the pres-ence of many orders of magnitude higher background. This comprises analysis by electric and magnetic fields, molecular dissociation, and Z identification in suitable detector systems (Figure 1). Almost all AMS facilities around the world are based on tandem accelerators [1]. This has the advantage of starting with nega-tively charged ions, which cannot be formed by certain stable isobars—the main background for radionuclide detection. For example, 14C is free from 14N interference, because ni-trogen does not form stable negative ions. The intense molecular isobars, 12CH2

and 13CH , break up in the ter-minal stripper (Figure 1). Similarly, the radionuclides 26Al, 55Fe, 68Ge, 129I, and 202Pb are free from stable-isotope interferences of 26Mg, 55Mn,

68Zn, 129Xe, and 202Hg, respectively. Sometimes it helps to start with nega-tively charged molecular ions (e.g., 41CaH3

, because 41KH3 does not form negative ions). In cases where stable isobar interferences persist because they also form negative ions, a separa-tion can be performed after accelera-tion with methods common to particle identification in nuclear physics. Here, higher energy helps and larger tandem accelerators with terminal voltages in the multi-MV range are useful. On the other hand, very small tandem accel-erators have been developed (TV = 0.2 – 0.5 MV) [1], which allow one to measure those radionuclides, which have very little background from stable isobars. This includes also the actinides, were no stable isobars exist.

The Vienna Environmental Research Accelerator (VERA)

VERA is a dedicated facility for AMS based on a 3-MV Pelletron tan-dem accelerator, and has been opera-tional at the University of Vienna for 20 years.

Early on, the goal was to develop VERA into an AMS facility for “all” isotopes, but this was originally re-stricted to radionuclides where no stable isobar interference exists (see above), with the exception of 10Be and later 36Cl. Even though these radionu-clides allow for a large range of appli-cations of AMS [2], many more would be of interest if the isobar interference problem could be solved in a more general way. Figure 2 displays the whole family of long-lived radionu-clides, which are of interest for AMS measurements. The figure shows that about half of the radionuclides (col-

ored in red and blue) would require a more involved isobar suppression.

Some time ago, exploratory experi-ments at the 14-MV Pelletron tandem accelerator of the Weizmann Institute demonstrated that the interaction of a laser with negative ions (anions) could in principle solve this problem [3]. This worked for cases where the binding energy (EA = electron affin-ity) of the extra electron of the un-wanted isobaric ion is smaller than the one of the wanted one. For example, the photodetachment of the electron from negative sulfur ions (EA = 2.08 eV) was achieved with photons of 2.33 eV (i.e., photons from a 532 nm Nd:YAG laser). These photons did not affect negative chlorine ions (EA = 3.61 eV), thus making a measurement of 36Cl without interference from 36S possible. However, a very low duty factor due to the use of a pulsed laser (10 ns pulse length at 30 Hz repetition rate), made the method impractical for AMS measurements.

The development of isobar sup-pression by photodetachment in a gas-filled radio-frequeny quadrupole ion guide at Oak Ridge National Labora-tory [4] was an important step toward an efficient laser–anion interaction system. At VERA, we have recently developed our own system based on this principle [5]. This laser–anion interaction system has now been cou-pled to the injector of the VERA AMS system (Figure 1).

The new VERA setup allows one to explore AMS measurements of a vari-ety of new isotopes. In a first AMS ex-periment, we studied the suppression of 36S and 26MgO with 532 nm laser photons for a 36Cl and 26AlO detec-tion. In both cases a dramatic suppres-

Twenty Years of VERA: Toward a Universal Facility for Accelerator Mass Spectrometry

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30 Nuclear Physics News, Vol. 27, No. 3, 2017

sion of the stable isobars by up to 1010 orders of magnitude was observed. In order to expand this method to other radionuclides, one has to know the re-spective electron affinities of atomic and/or molecular anions. This informa-tion is currently incomplete and needs to be investigated. Tunable lasers will allow us to measure electron affinities of hitherto unknown anion species, in order to find those which are most suit-able for isobar suppression.

Some AMS Applications at VERABoth cosmogenic and anthropo-

genic radionuclides penetrate many sections of our environment at large,

and AMS with its ultra-low atom counting sensitivity makes it possible to use these radionuclides as prox-ies for processes in a variety of fields [2]. To demonstrate the versatility of VERA, we discuss a few highlights from the work during the past 20 years.

ArchaeologyBecause very little sample material

is needed for a 14C AMS measure-ments, precious objects can be dated. Thus, we were allowed to take small samples from the teeth of a human skull, which was found more than 100 years ago in a cave in Moravia and preserved in the Anthropology

Department of the Natural History Museum of Vienna. Our 14C measure-ments revealed an age of 34,000 years for this object [6], contributing to the questions of the first appearance of anatomically modern humans in Cen-tral Europe.

In the framework of a 10-year col-laboration with archaeologists and Egyptologists we studied the Synchro-nisation of Civilisations in the Eastern Mediterranean in the Second Millen-nium BC (SCIEM 2000 project). For this project we performed extensive 14C dating at a site in the Nile Delta, which is crucial to establish an abso-lute chronology in the Late Bronze

Figure 1. Schematic layout of the VERA AMS facility in its current configuration. The original facility became operational in 1997, and has since gone through several upgrades in order to accommodate “all” isotopes.

I on L aser I nter- A ctionM ass S pectrometry

Source140 Samples

∆E/E-Detector

∆E/E-Detector 14C,26Al Detection

36Cl Detection

10Be Detection

Einzel LensBeam Switch

Focus75 kV Preacceleration

Electrostatic AnalyzerE/q = 90 keV r = 0.300 m

Magnetic QuadrupoleDoublet

Multi Beam Switcher

Injection MagnetME/q2

= 17 MeV amur = 0.457 m

Cs-Beam SputterSource for

Negative Ions

x/y-Steerer

y-Steerer

Electrostatic AnalyzerE/q = 4.4 MeV r = 2.000 m

MagneticQuadrupoleDoublet withx/y-Steerer

Magnetic QuadrupoleTriplet

Analyzing MagnetME/q2

= 176 MeV amur = 1.270 m

SiN absorber+∆E/E-Detector

Focus30 kV Preacceleration

Source240 Samples

PIXE - ART

Bending Magnet 90°ME/q2

= 8.3 MeV amur = 0.350 m

Electrostatic AnalyzerE/q = 60 keV r = 0.300 m

+ 3 MV Tandem Accelerator

Einzel Lens

Vienna Environmental Research Accelerator

x/y-Slits

x/y-Slits

x-Slits

x/y-Slits

x/y-Slits

x/y-Slits

x/y-Slits

x/y-Slits

x/y-Slits

Ion Beam Attenuator

Ion Beam Attenuator

Ion Production and Detection Electrostatic Components Magnetic Components Beamline

Insertable Faraday Cup Beam Profile Monitor

RFQion cooler

Laser setup

Power meter

x/y-Steerer

ChargingChainGas + Foil

StripperEinzel Lensx/y-Steerer

OffsetFaraday Cups

ElectrostaticQuadrupole Triplet

x/y-Steerer

y-Steerer

OffsetFaraday Cups

Analyzing MagnetME/q2

= 176 MeV amur = 1.270 m

E-Detector

TOF-DetectorHeavy Isotope Detection

y-Steerer

SwitchingMagnetB = 1.66 T

Wienfilter xB = 35 kV/cm x 0.4 Tε

Stable IsotopeMeasurement

x-Slits

status 2017

Experimental Station

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Vol. 27, No. 3, 2017, Nuclear Physics News 31

Age [7]. In this case a difference of 120 years was found between the time scale established by 14C dating and by archaeological reasoning, respec-tively. A similar difference shows up for the date of the famous volcanic eruption of Santorini in the Aegean around 1600 BC. Great efforts are on the way to resolve this persistent dis-crepancy, with evidence emerging that the archaeological time scale probably needs some correction to arrive at a consensus with the 14C chronology.

The Ugly and the Beautiful: The 14C Bomb Peak

In the early 1960s, the 14C content of the atmosphere sharply increased through the intense postwar nuclear weapons testing program of the su-per powers. After the nuclear test ban treaty of 1963, the CO2 cycle trans-

ferred this 14C excess to the biosphere and the oceans. This created the so-called 14C bomb peak with a rapidly changing 14C signature in the second half of the 20th century (see inset (a) in Figure 3). Among the applications resulting from this unique signature, the retrospective determination of the birth date of cells in the human brain by a group of cell biologists at the Kar-olinska Institute in Stockholm stands out [8]. In a collaboration with this group, we measured 14C in the DNA extracted from neurons in the olfactory bulb [9], with no indication for neuro-genesis (see inset (b) in Figure 3). This investigation required 14C AMS mea-surements in carbon samples of only a few micrograms. Later the Stockholm group found a finite renewal of neu-rons in the hippocampus, one of the most important parts of our brain.

The Negative Hydrogen Molecule, H2‒

The formation of first stars in the early universe requires the formation of H2 molecules for cooling, and one of the possible pathways is the reac-tion H‒ + H → H2

‒ → H2 + e‒. The first prove of the existence of H2

‒ with a minimum lifetime of a few micro-seconds was demonstrated at VERA through the simultaneous detection of the two protons after the dissociation of H2

‒ in the terminal stripper of the tandem accelerator [10]. In a collabo-ration with the Weizmann Institute in Rehovot, the lifetime of H2

‒ was de-termined to be 8 µs with an ion trap experiment [11]. Coulomb explosion experiments at the Max Planck Insti-tute in Heidelberg revealed a high-an-gular momentum inter-nuclear wave function of this molecule [12]. These results will have some bearing on the

14C(5.7x10-3)

26Al(0.72)

129I (15.7)

236U (23.4)

10Be (1.4)

36Cl (0.30)

41Ca (0.10)

60Fe(2.1)

99Tc (0.21)

53Mn (3.7)

244Pu (80) 242Pu (0.38)

243Am (7.4x10-3) 240Pu (6.6x10-3)

239Pu (2.4x10-2) 237Np (2.1)

233U (0.16)

210mBi (3.0)

202Pb(5.3x10-2)

55Fe (2.7x10-6)

68Ge (7.4x10-7)

79Se (0.38)

93Zr (1.6)

92Nb (36)

94Nb (2x10-2) 107Pd (6.5)

126Sn (0.22)

135Cs (2.3)

137La (6x10-2)

146Sm (68)

150Gd (1.8)

154Dy (3.0)

182Hf (8.9)

186mRe (0.2)

208Bi (0.37)

205Pb (17.3)

Radionuclides for AMS (half-life in Myr) Now possible at VERA tandem (3 MV) Large tandem facilities required (14 MV) Isobar separation presently impossible

neutron number

prot

on n

umbe

r

Figure 2. Display of radionuclides which are of interest for AMS measurements. Half-lives are given in brackets in units of million years. The green color marks radionuclides that can be measured at smaller AMS facilities like VERA, whereas those that can currently only be measured at larger facilities are marked in red. The ones marked in blue require special isobar suppression, which at VERA will be accomplished with the new laser–anion interaction region (Figure 1).

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32 Nuclear Physics News, Vol. 27, No. 3, 2017

description of the complex molecular processes in the early universe.

PIXE of Silver Point Drawings of Albrecht Dürer

Among the work of the famous renaissance painter Albrecht Dürer (1471–1528) are silver point drawings that have been investigated with vari-ous analytical techniques by a group of scientists at the Louvre Museum in Paris. In a collaboration with this group, we performed proton induced

X-ray emission (PIXE) spectroscopy experiments at VERA for four origi-nals silver point drawings from the Al-bertina Museum in Vienna [13]. These comprise the earliest self-portrait of Dürer when he was only 13 years old (1484), and also a portrait of his father from two years later. A striking differ-ence between the two drawings was the ground layer, consisting mainly of bone white for the former, and a large admixture of lead white for the latter. Trace element analysis in the ground

layer and in the silver point material did not allow, however, for solving the question whether the more advanced drawing of Dürer’s father was actually a self portrait of his father or made by the young Dürer himself. More ana-lytical work is necessary to come to a conclusion on this interesting question.

Multi-Actinide AnalysisAt VERA we developed AMS

measurements for the simultaneous analysis of very low concentrations of

14N → 14C + p

Cosmic rays (p)

Atmosphere (N, O, Ar)

n

n

14CO2

O2

Plants + Oceans (14C)

Biosphere (14C) (a) (b)

Figure 3. Picture of the first hydrogen bomb test of the United States in 1952. The simplified reaction schematic indicates that neutrons from the bomb tests convert 14N into 14C, just like the neutrons emerging from the spallation of atmospheric nuclei with high-energy protons from cosmic rays. This led in 1963 to a doubling of the 14C/12C ratio in atmospheric CO2, creating the “14C bomb peak” shown on the inset (a). Here, the 14C content of DNA extracted from cells of a human who lived in the second half of the 20th century allows one to retrospectively determine the birth date of the respective cells. Adapted from [8]. Inset (b) demonstrate that neurons of the olfactory bulb from five individuals born before the bomb peak do not show any excess 14C, signaling the absence of forming new neurons after birth. Adapted from [9].

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Vol. 27, No. 3, 2017, Nuclear Physics News 33

233,236U, 237Np, 239,240,242Pu, 243Am, and 248Cm from ground- and seawa-ter samples [14]. This method does not require an elaborate chemical pre-separation of the different elements, and is thus particularly useful for fi eld studies of actinide migration in natu-ral rock formations. In collaboration with the Institute for Nuclear Waste Disposal of the Karlsruhe Institute of Technology (KIT), such measure-ments were performed for the Col-loid Formation and Migration (CFM) project at the deep underground rock laboratory of the Grimsel Test Site (GTS) in Switzerland. A concentra-

tion sensitivity below ppq (10–15) was reached for some of the radionuclides. With proper normalization with a multi-actinide standard, a quantitative assessment of radionuclide migra-tion in natural environments has been achieved [14].

Live 244Pu on EarthThe longest-lived plutonium iso-

tope is the neutron rich nuclide 244Pu, with a half-life of 80 million years (Figure 2). It can only be produced in stellar environments with very high neutron fl uxes, possibly in superno-vae. For such events that are suffi -

ciently close in time and distance, and with reasonable assumptions about their frequency, one expects that some of the synthesized and ejected 244Pu nuclides end up in slowly accu-mulating archives on Earth. We have investigated deep-sea manganese crusts for such signals, and found ap-proximately a factor of 10 less 244Pu nuclides than expected from super-novae production [15]. Our results indicate that 244Pu may have been produced in rare binary neutron star mergers, an alternative stellar envi-ronment for high-neutron-fl ux syn-thesis of heavy nuclides. Theoretical

292Eka-Th Search for SHE nuclides in Nature Positive evidence from ICP-SF-MS: Marinov et al., Jerusalem, 2007, 2009, 2010 Upper limits from AMS: Lachner et al., Munich, 2008 Dellinger et al., VERA, 2010, 2011 Ludwig et al., Munich 2012

< 5 × 10-13

< 6 × 10-14

< 7 × 10-16

< 2 × 10-15

< 4 × 10-15

< 3 × 10-16

(1-10) × 10-10

~ 1 × 10-12

211,213,217,218Th: (1-10) x 10-11, <8 x 10-15

Nh

Fl

Mc

Lv

Ts

Og 118

120

122

Figure 4. Summary of the results for searches of SHE nuclides in terrestrial materials [16], depicting the upper end of the chart of nuclides. The shades of grey in the background indicate the relative stability of nuclides due to shell model cor-rections (darker means more stable). Nuclides marked in orange have been measured with AMS. Abundance limits with respect to the corresponding host material (e.g., Rg isotopes (Eka-Au) were searched for in gold nuggets) are given in the violet boxes. The positive evidence of the Marinov experiments is shown in the blue boxes. References to the various experi-ments indicated in the top-left insert can be found in Ref. [16].

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34 Nuclear Physics News, Vol. 27, No. 3, 2017

consideration support such an exotic astrophysical scenario.

Search for Superheavy Elements in Terrestrial Materials

Some 50 years ago, a neutron-rich “island of stability” beyond the heavi-est known nuclei was predicted by nuclear shell model theories. These nuclei were nicknamed SHEs (super-heavy elements). Since it was clear from the onset that this island cannot be reached by heavy ion nuclear reac-tions in the laboratory with available projectiles and targets, many searches were performed to find minute traces of primordial SHE nuclides in na-ture. However, such nuclides would have to have half-lives of at least 100 million years in order to survive in measureable quantities the 4.5 billion years since the solar system formed. After reports of a positive evidence for the existence of SHEs from mea-surements with inductively coupled plasma sector field mass spectrom-etry (ICP-SF-MS) by a group from the Hebrew University in Jerusalem, two AMS labs set out to check these claims. The AMS group at the Maier Leibniz Laboratory in Munich per-formed AMS experiments at their 14-MV tandem accelerator and the VERA lab used the 3-MV tandem ac-celerator. A summary of these efforts is presented in Ref. [16] and Figure 4. These experiments did not find any trace of SHEs with concentration lim-its many orders of magnitude lower than the positive claims. They also in-cluded searches for 42 additional SHE nuclides covering part of the center of the island of stability around mass 300 (Z = 114, N = 184). Again no evidence for the existence of SHE nuclides was found [16].

ConclusionIn 1977, accelerator mass spec-

trometry was introduced at Berkeley, Rochester, and McMaster University [2]. Therefore in 2017 the 40th an-niversary of AMS will be celebrated at the tri-annual AMS Conference in Ottawa (AMS-14). Currently there are more than 100 AMS facilities world-wide [1], utilizing long-lived radionu-clides to study a multitude of fields in every domain of our environment at large. Through its recent addition of a laser–anion interaction (Figure 1), VERA will be able to substantially increase the number of radionuclides available for AMS measurements (Figure 2). This promises an exciting future of AMS at VERA for the years to come.

AcknowledgmentsWe gratefully acknowledge the col-

laboration with the many students and colleagues from Vienna and abroad. We particularly thank the colleagues who worked with us during the past 20 years at VERA: Alfred Priller, Pe-ter Steier, and Eva Maria Wild.

References 1. H.-A. Synal, Int. J. Mass Spectr. 349–

350 (2013) 192. 2. W. Kutschera, Int. J. Mass Spectr.

349–350 (2013) 203. 3. D. Berkovits et al., Nucl. Instr. Meth.

A 281 (1989) 663. 4. Y. Liu et al., Appl. Phys. Lett. 87

(2005) 113504. 5. M. Martschini et al., Int. J. Mass

Spectr. 415 (2017) 9. 6. E. M. Wild et al., Nature 435 (2005)

322. 7. W. Kutschera et al., Radiocarbon 54

(2012) 407. 8. K. L. Spalding et al., Cell, 122 (2005)

133.

9. O. Bergmann et al., Neuron 74 (2012) 634.

10. R. Golser et al., Phys. Rev. Lett. 94 (2005) 223003.

11. O. Heber et al., Phys. Rev. A 73 (2006) 060501(R).

12. B. Jordon-Thaden et al., Phys. Rev. Lett. 107 (2011) 193003.

13. P. Milota et al., Nucl Instr. Meth. B 266 (2008) 2279.

14. F. Quinto et al., Anal. Chem. 87 (2015) 5766.

15. A. Wallner et al., Nature Communica-tions 6 (2016) 5956.

16. G. Korschinek and W. Kutschera, Nucl. Phys. A 944 (2015) 190.

Robin GolseR

University of Vienna, Vienna, Austria

WalteR KutscheRa

University of Vienna, Vienna, Austria

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meeting reports

Vol. 27, No. 3, 2017, Nuclear Physics News 35

The 26th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Quark Matter 2017, was held in Chicago, Illinois, USA on 5–11 February 2017. Quark Matter is the major conference series in the field of high-energy heavy-ion physics, ap-proaching a 40-year history. The first in this series took place in Darmstadt in 1980. Since then, the conferences have been organized approximately every 1.5 years. The three most recent meetings before Chicago were held in Kobe, Japan in September 2015; Darmstadt, Germany in May 2014; and Washington, D.C., USA in August 2012. The scientific topics covered at the meeting included both experimen-tal and theoretical QCD studies of nu-clear matter at high temperatures and/or baryon densities, created in nuclear collisions at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory and the Large Hadron Collider at CERN. Over 700 participants (over half of them stu-dents and young scientists) gathered in Chicago to present and discuss their work in talks and posters covering a broad range of topics in the field.

In the Quark Matter 2017 open-ing ceremony, conference participants were greeted by Illinois Representa-tive Raja Krishnamoorthi, Deputy Mayor of the City of Chicago Steve Koch, and the Associate Director for Nuclear Physics of the U.S. Depart-ment of Energy Dr. Timothy Hall-man. The keynote speaker of the ses-sion was Dr. Jürgen Schukraft, who summarized the status of the field ahead of new results to be presented at the conference and posed several important open questions yet to be answered. The main program of the

conference was opened with a day of plenary talks and a poster session; the next two days were dedicated to selected parallel talks; and the re-maining time was allocated to plenary presentations. Over 500 presentations were made at the meeting, including 38 invited plenary talks, 176 parallel talks, and over 300 posters. Eight of the poster presentations were selected by the conference Awards Commit-tee for a flash talk presentation in the last plenary session. Parallel sessions of the conference focused on topical discussions; the list of parallel session topics included Initial State Physics and Approach to Equilibrium; Jets and High-pT Hadrons; Electromagnetic Probes; QCD in Small Systems; QCD at High Temperature; Chiral Magnetic Effect, Vorticity and Spin Polariza-tion; Quarkonia and Open Heavy Fla-vours; Baryon-Rich QCD Matter and

Astrophysics; Collective Dynamics; New Theoretical Developments; Cor-relations and Fluctuations; and Future Experimental Facilities, Upgrades, and Instrumentation.

The conference highlighted many advances in theory and results from experimental studies of heavy ion col-lisions. PHENIX and STAR presented a harvest of new results from RHIC’s heavy flavor program, including first ever measurements of baryon to me-son ratios in the charm sector. The RHIC experiments extended their sys-tematic studies of collective flow in AuAu collisions to higher precision measurements in the charmed sector, and to detailed studies of asymmet-ric collision systems. Hydrodynamic behavior of the quark-gluon plasma medium was tested meticulously by a suite of identified particle flow results from all three LHC experiments, in

Figure 1. Electromagnetic probes; QCD in small systems; QCD at high temper-ature; Chiral Figure 1. Jürgen Schukraft delivered a keynote talk “Status and Key Open questions” in the opening session of Quark Matter 2017 conference.

The 26th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Quark Matter 2017

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36 Nuclear Physics News, Vol. 27, No. 3, 2017

both PbPb and pPb collisions. These new LHC measurements so far span the first two generations of quark flavors, but bottom hadron measure-ments are now also within experimen-tal reach. Surprising new findings of the evolution of the charge-separation signal observed in azimuthal correla-tions from AuAu collisions at RHIC to PbPb and pPb events at the LHC generated a robust discussion whether the observations are indeed caused by the chiral magnetic effect as previ-ously argued for the RHIC data. The exploration of hard probes has seen an explosion of novel methods and ob-servables advancing the understand-ing of jet quenching phenomena: both RHIC and LHC experimentalists pre-sented results on jet mass, jet shape, and splitting function measurements, exploring jet–medium interactions in ever finer detail.

Theory highlights included im-provements in the modeling of the early pre-equilibrium stage in heavy ion collisions, as well as deeper ex-plorations of the profound impact of initial state fluctuations on the overall event dynamics and on probes that are used to study the quark-gluon me-dium at different scales. Very impres-sive advances made in the data-driven determination of QGP parameters from global Bayesian analysis were undoubtedly one of the highlights of the Chicago meeting. Overall, signifi-cant progress continues to be made in the development of a comprehen-sive theoretical description and dy-namical modeling of the entire evo-lution of heavy ion collisions, from the initial stage to the formation of a quark-gluon plasma and its eventual hadronization, from the bulk (hydro)

dynamic evolution of the quark-gluon medium to its tomography with the help of jet–medium interactions, and from large to small systems. Tell-ingly, the complexity of the field has recently led to an increased number of collaborative efforts within the theory community, following the long-stand-ing tradition established on the experi-mental side: the BEST, THOR, JET, and JETSCAPE Collaborations all presented results from and/or future plans for these joint efforts.

The conference was concluded by an awards ceremony highlight-ing achievements of a number of young scientists. Björn Schenke of Brookhaven National Labora-tory was presented with the 2017 Zimányi Medal in Nuclear Theory, for his pioneering work in modeling the dynamics of heavy ion collisions. Zhoudunming Tu (Rice University) and Azumi Sakai (Sophia University) won Nuclear Physics A Young Scien-tist Awards for the best experimental and theoretical talks, respectively, presented in the parallel sessions. At the end of the awards ceremony the organizers of the 27th edition of the conference unveiled details of Quark Matter 2018: that meeting will be held in Venice, Italy, on 13–19 May 2018.

Among the main objectives of the Quark Matter conferences is fulfill-ing an educational mission: to help raise the next generation of scientists. Bringing world-renowned experimen-tal and theoretical physicists of the field together with young postdocs and students to discuss the latest de-velopments and advances in the field is only a part of this mission. In addi-tion, the first day of the conference has traditionally been entirely devoted to

offering a set of introductory lectures to students and young scientists. Fol-lowing this tradition, the organizers of Quark Matter 2017 invited once more a team of expert speakers to discuss the foundations of the field, new ex-perimental methods, and recent theo-retical advances in deciphering the signals from quark gluon plasma. The Student Day attendance at the Chi-cago meeting exceeded all previous records—about 400(!) participants registered for this special event. A contributing factor to this success is that Quark Matter conferences have established the custom of providing financial support for large numbers of students and young postdocs from all nations to facilitate their attendance at this most important conference in the field. Generous contributions from a large number of national and interna-tional supporters made it possible this time to provide travel support to more than 300 young participants.

Additional information about the Quark Matter 2017 Conference, in-cluding program details and presenta-tion materials as well as conference photos, is available on our homepage at http://qm2017.phy.uic.edu.

Russell Betts

Illinois Institute of Technology, Chicago, Illinois, USA

Olga evdOkimOv

University of Illinois at Chicago, Chicago, Illinois, USA

ulRich heinz

Ohio State University, Columbus, Ohio, USA

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meeting reports

Vol. 27, No. 3, 2017, Nuclear Physics News 37

On 17 March 2017, Jefferson Lab, in Newport News, Virginia, hosted a workshop exploring potential uses of its Low Energy Recirculator Facility (LERF; Figure 1). The goal of this workshop was to inform researchers and educators of opportunities at the LERF facility, and to explore its re-search and educational potential. The LERF, which houses an energy recov-ery linac and seven user labs, provides excellent opportunities for funda-mental and applied science research as well as education and training. In addition to the 170 MeV, high-current, recirculating accelerator, the facility possesses state-of-the-art equipment for pulsed laser deposition, micro-machining, XHV vacuum work, laser-generated TeraHertz with associated instrumentation, and pulsed fiber laser development.

The one day “Workshop on Sci-ence at LERF” was organized into several topical sessions dealing with science using the LERF beam, and science possible with the LERF lab equipment. A tour of the Old Domin-ion University Area Research Center (ODU ARC) and LERF labs was or-ganized for workshop participants, and a panel discussion concluded the workshop proceedings. The workshop scientific program and presentations are available at https://www.jlab.org/indico/event/199/. The workshop at-tracted 51 registered participants from Jefferson Lab, NASA, and nearby uni-versities, considerably exceeding ini-tial expectations.

After presentations describing how outside projects are carried out at Jef-ferson Lab stressing the need for safety and careful resource management and a historical perspective of the facility, there were several talks about poten-

tial uses of the LERF for nuclear phys-ics, isotope production, and positron production. All of these applications would use the facility accelerator. The LERF complements CEBAF as a nuclear physics accelerator by pro-viding low energy beam at high cur-rent. With an internal target one can, in principle, preserve the beam quality well enough after the target to allow energy recovery. In addition to this, when operated as a single pass device for isotope or positron production, the accelerator can provide over 100 kW of beam power to a target. Since the beam is also very bright with a very small energy spread, it can be used as an extremely bright source of low en-ergy positrons.

After a tour of the facility and the ODU labs at Jefferson Lab, the talks concentrated on user experiments in the User Labs that did not neces-sarily use the FEL. A representative from Virginia Diodes described po-tential uses and applications of THz radiation, and two previous users of the LERF facility gave summaries of how they used the LERF User Labs to carry out user programs in nanotubes

and Materials Research. The equip-ment available in the ODU labs at the lab was then described. The last talk discussed possible laser applications that might be developed in the LERF. They range from THz production, to production of electron beams with an-gular momentum, to next-generation photocathode drive lasers.

At a Panel Discussion, new av-enues for research support were dis-cussed as well as some new potential applications. One new application was the use of the facility Laser Micro-Engineering Station to fabricate THz waveguides. It was also pointed out that there is a very strong need for bright low energy positron sources and it may be possible to sell time at a positron use facility. It was agreed to put together a proposal for a Scientific Users Workshop of low energy posi-trons to make the science case for such a facility.

S. BenSon Jefferson LAB

G. Krafft Jefferson LAB, ODU

Jefferson Lab Hosts Workshop on New Scientific Applications of its Low Energy Recirculator Facility

Figure 1. LERF workshop participants.

Page 40: Nuclear Physics News - NuPECCeditorial Vol. 27, No. 3, 2017, Nuclear Physics News 319 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search

news and views

38 Nuclear Physics News, Vol. 27, No. 3, 2017

When the European Science Foun-dation (ESF) was created in 1974, the case was made for an organization that would bring together the continent’s leading scientists and funding agen-cies to advance European science. ESF was set up as a coordinating body for Europe’s research funding and research performing organizations. Over the four decades that followed, our organization took on the tasks of supporting cross-border collaborative research and on setting strategic sci-ence agendas for Europe, and it has achieved an enormous and lasting im-pact on the science community within Europe and at the international level.

ESF has supported over 2,000 pro-grams and networks, gathering more than 300,000 scientists from 186 coun-

tries through funding from 80 Member Organizations in 30 countries. It has also enabled the creation or nurtured the development of six Expert Boards and Committees in various thematic areas, including the Nuclear Physics European Collaboration Committee (NuPECC). Most of the scientists who have thus become involved with ESF over the years continue to put their trust in our organization. ESF has con-tributed to some of the most important policy and scientific developments that have taken place over that period of intense European evolution.

Another period has started since 2010. Although our traditional mission of funding programs and networks has unfortunately stopped, ESF was able to adapt in order to survive. Not sur-

prisingly, it is through our expertise in evaluating, funding, and managing research programs and networks, and through the overall heritage of ESF, that we are now able to offer new ser-vices to the community at large. Our team of experts has an excellent un-derstanding of the needs of the Euro-pean Research Area and we also have longstanding connections throughout the international research community.

On 3 April 2017 I was delighted to mark the establishment of Science Connect (Figures 1 and 2), the ESF’s scientific services division and the core of our future mission. After 43 years of success in stimulating Euro-pean research through our networking, funding, and co-ordination activities, the ESF will continue to contribute

ESF After ESF: The Launch of Science Connect

European research through our networking, funding, and co-­‐ordination activities, the ESF will continue to

contribute strongly to the development of the European Research Area.

<LE>Figure 1. The ESF-­‐Science Connect launch event in Strasbourg City Hall on 3 April 2017 was attended by

senior figures from the worlds of research, academia, political actors, and public life.</LE>

<AQ> Figure 1 and 2 text callouts okay?</AQ>

We will do this by enabling and supporting the science community and science stakeholders with

unique strengths, insights, and technical capabilities—partnering with customers in leading successful

projects and facilitating informed decision making through evidence-­‐based science and through a wide

range of support services. In brief, our functions cover five key areas:

• <BL>Peer review—where we identify the best research and optimize the use of our partners’

internal resources.

• Evaluation—where we work to maximize the impact of policies and programs to facilitate the

achievement of research excellence.

• Career tracking—where we generate high quality, reliable information on supply and demand for

doctorate holders and their overall availability and mobility in the European Research Area.

• Programme and Project Management and Administration—this alleviates the administrative

burden on research infrastructures and contributes to research success.

• Host for several internationally recognized Expert Boards and Virtual Institutes—where we provide

effective secretariats, hosting platforms, organizational structures, and strategic advice.</BL>

Today these Expert Boards include NuPECC, and also the European Space Sciences Committee (ESSC) and

the Committee on Radio Astronomy Frequencies (CRAF). We continue to lead joint projects with the

Figure 1. The ESF-Science Connect launch event in Strasbourg City Hall on 3 April 2017 was attended by senior figures from the worlds of research, academia, political actors, and public life.

European Marine Board based in Ostend and are looking forward to a renewed remit for the MatSEEC

committee on materials science. In addition, we hope that recent discussions will soon lead to new entities

being set up by ESF, and to existing ones being hosted at the ESF Headquarters in Strasbourg.

Overall, we have a highly qualified international and interdisciplinary team with a deep understanding of

science matters and research infrastructures across Europe. Through Science Connect, we are providing

that experience, along with forward thinking and planning, to all our members, partners, and customers,

both public and private. We are currently engaged in over a dozen key projects including participation as

Partner or Coordinator in the highly visible European Commission’s Graphene Flagship or in the inventory

and web portal of European research infrastructures MERIL.

We are also expanding our resource network of research expertise and talent by establishing the

ESF Community of Experts. Our Community of Experts reactivate the ESF network of international

academics, science policy experts, key decision-­‐makers, and stakeholders across the European and global

research landscape. We already have over 2,200 new members on board, including our College of Review

Panel members and our College of Research Associates. Find more at: http://www.esf.org/why-­‐us/our-­‐

community-­‐of-­‐experts/.

We are now looking forward with confidence, energy, and enthusiasm to our continuous further

contribution to science and science-­‐related activities over Europe.

JEAN-­‐CLAUDE WORMS

ESF Chief Executive

<LE>Figure 2. The President and Chief Executive with Dr Gabriele-­‐Elisabeth Körner, NuPECC Executive

Scientific Secretary, and colleagues and staff from the former MatSEEC expert committee.</LE>

Figure 2. The President and Chief Executive with Dr Gabriele-Elisabeth Körner, NuPECC Executive Scientific Secretary, and colleagues and staff from the former MatSEEC expert committee.

Page 41: Nuclear Physics News - NuPECCeditorial Vol. 27, No. 3, 2017, Nuclear Physics News 319 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search

news and views

Vol. 27, No. 3, 2017, Nuclear Physics News 39

strongly to the development of the Eu-ropean Research Area.

We will do this by enabling and supporting the science community and science stakeholders with unique strengths, insights, and technical ca-pabilities—partnering with custom-ers in leading successful projects and facilitating informed decision making through evidence-based science and through a wide range of support ser-vices. In brief, our functions cover five key areas:

Peer review—where we identify the best research and optimize the use of our partners’ internal resources.

Evaluation—where we work to maximize the impact of policies and programs to facilitate the achievement of research excel-lence.

Career tracking—where we gen-erate high quality, reliable infor-mation on supply and demand for doctorate holders and their overall availability and mobility in the European Research Area.

Programme and Project Manage-ment and Administration—this alleviates the administrative bur-den on research infrastructures and contributes to research suc-cess.

Host for several internationally recognized Expert Boards and

Virtual Institutes—where we pro-vide effective secretariats, hosting platforms, organizational struc-tures, and strategic advice.

Today these Expert Boards include NuPECC, and also the European Space Sciences Committee (ESSC) and the Committee on Radio Astronomy Fre-quencies (CRAF). We continue to lead joint projects with the European Ma-rine Board based in Ostend and are looking forward to a renewed remit for the MatSEEC committee on materials science. In addition, we hope that re-cent discussions will soon lead to new entities being set up by ESF, and to existing ones being hosted at the ESF Headquarters in Strasbourg.

Overall, we have a highly quali-fied international and interdisciplinary team with a deep understanding of sci-ence matters and research infrastruc-tures across Europe. Through Science Connect, we are providing that experi-ence, along with forward thinking and planning, to all our members, part-ners, and customers, both public and private. We are currently engaged in over a dozen key projects including participation as Partner or Coordinator in the highly visible European Com-mission’s Graphene Flagship or in the inventory and web portal of European research infrastructures MERIL.

We are also expanding our resource network of research expertise and tal-

ent by establishing the ESF Commu-nity of Experts. Our Community of Experts reactivate the ESF network of international academics, science policy experts, key decision-makers, and stakeholders across the European and global research landscape. We al-ready have over 2,200 new members on board, including our College of Re-view Panel members and our College of Research Associates. Find more at: http://www.esf.org/community-of-experts/.

We are now looking forward with confidence, energy, and enthusiasm to our continuous further contribution to science and science-related activities over Europe.

ORCIDJean-Claude Worms

http://orcid.org/0000-0002-0851-7341

Jean-Claude Worms ESF Chief Executive

PROMOTE AWARENESS OF YOUR FUTURE EVENTS

Send the pertinent information to [email protected]

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news and views

40 Nuclear Physics News, Vol. 27, No. 3, 2017

The construction of the interna-tional accelerator facility FAIR (Facil-ity for Antiproton and Ion Research) has begun. The start of building con-struction and civil engineering work is a crucial moment for one of the largest construction projects for scientific re-search worldwide. On 4 July 2017, the groundbreaking ceremony (Figure 1) was held for the large ring accelerator SIS 100, which will be the key compo-nent of the future accelerator facility FAIR. The construction site is located to the northeast of GSI Helmholtz-zentrum für Schwerionenforschung in Darmstadt.

FAIR will be a unique particle ac-celerator facility with an investment volume of more than €1 billion. The facility is being constructed by nine partner countries and is scheduled to go into full operation in 2025. Around 3,000 scientists from all over the world will work at FAIR, where they will gain groundbreaking in-sights into the structure of matter and the development of the universe. The key component of FAIR will be an underground ring accelerator with a

circumference of 1,100 meters. Con-nected to it is a complex system of storage rings and experimental sta-tions. Scientists will be able to study the universe in the lab: FAIR will ad-dress fundamental problems such as the origin of heavy elements in the universe or the structure of neutron stars, but also applications from ma-terial sciences to medicine.

Over the past few weeks and months, extensive preparations have been made for the huge construction project. For example, work is already under way to connect the existing ac-celerator facilities of the GSI Helm-holtzzentrum to the new FAIR com-plex. Retaining walls are being built and contracts have been awarded for the excavation and installation of the ring tunnel following a successful call for bids. These were important prepa-ratory steps for the large-scale work on the FAIR infrastructure, which has now begun with the groundbreaking ceremony for the SIS 100 ring acceler-ator. The cutting-edge accelerator and experiment facilities will be installed after the new buildings are completed.

At the ceremony, government of-ficials and scientists from Germany and abroad extended greetings and symbolically broke the ground with a shovel. This crucial milestone was attended by representatives from all nine partner countries.

In line with the groundbreaking ceremony, FAIR also began FAIR Phase 0 of its experimentation pro-gram in order to harmonize research operations with the progress of con-struction. Beam times are already be-ing scheduled for researchers at exist-ing GSI facilities and at components for FAIR. To conduct this research, scientists are using the GSI accelera-tor facilities, which have been sub-stantially enhanced for their later use as preaccelerators for FAIR and will have their technology further up-graded in the future. Moreover, parts of FAIR can already be used, includ-ing the CRYRING storage ring.

Ingo Peter

GSI Darmstadt

An Important Milestone: Groundbreaking Ceremony for the FAIR Accelerator Facility

Figure 1. Groundbreaking ceremony for the FAIR facility.

Page 43: Nuclear Physics News - NuPECCeditorial Vol. 27, No. 3, 2017, Nuclear Physics News 319 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search

calendar

2017September 25–29

Salamanca, Spain. XVII Inter-national Conference on Hadron Spectroscopy and Structure HAD-RON2017

http://hadron2017.usal.es/

September 25–30Halong City, Vietnam. ISPUN

2017https://ispun.vn/

October 2–5Moscow, Russia. 3rd Interna-

tional Conference on Particle Phys-ics and Astrophysics ICPPA-2017

http://indico.cfr.mephi.ru/event/14/

October 5–7Sofia, Bulgaria. Shapes and Dy-

namics of Atomic Nuclei: Contem-porary Aspects SDANCA-17

http://ntl.inrne.bas.bg/events/sdanca17/

October 9–13München, Germany. The Dark

Universe 2017http://www.darkuniverse2017.

physik.uni-muenchen.de/

October 15–20Amboise, France. 20th Colloque

GANILhttps://ganilcolloque.sciencesconf.

org/

October 15–20CERN Geneva, Switzerland.

17th International Conference on Ion Sources

http://icis2017.web.cern.ch/

October 15–21Catania, Italy. Neutrino and Nu-

clear Physics 2017 (CNNP 2017)https://agenda.infn.it/

conferenceDisplay.py?confId=12166

October 16–18Beijing, China. CUSTIPEN-Bei-

jing Workshop on RIB Science - 2nd China-US-RIB Meeting

http://custipen.pku.edu.cn/meeting/2nd-china-us-rib/

October 23–27Havana, Cuba. LASNPA-WONP-

NURT 2017http://www.wonp-nurt.cu/pages/

index.php

October 29–November 4Paphos, Cyprus. 12th European

Research Conference on Electro-magnetic Interactions of Nucleons and Nuclei (EINN 2017)

http://einnconference.org/2017/

November 1–4Tokyo, Japan. IIRC symposium

“Perspectives of the physics of nu-clear structure”

http://indico.cns.s.u-tokyo.ac.jp/conferenceDisplay.py?confId=316

November 6–10Gif-sur-Yvette, France. SSNET

2017 Conferencehttps://indico.in2p3.fr/event/1400

November 13–17Melbourne, Australia. A Celebra-

tion of CEMP and Gala of GALAHhttps://indico.fnal.gov/

conferenceDisplay.py?confId=13478

November 13–18Kanazawa, Japan. 10th Interna-

tional Conference on Nuclear Phys-ics at Storage Rings (STORI’17)

http://indico2.riken.jp/indico/conferenceDisplay.py?confId=2581

November 15–17College Station, TX, USA. Ex-

ploring the Nuclear Frontier: 50 years of beam

http://cyclotron.tamu.edu/50years/

2018February 19–25

Bormio, Italy. BORMIO-2018: The IV Topical Workshop on Mod-ern Aspects in Nuclear Structure

https://sites.google.com/site/wsbormiomi2018/

February 26–March 2GSI Darmstadt, Germany. NU-

STAR Annual Meeting 2018https://indico.gsi.de/

conferenceDisplay.py?confId=5843

April 17–20Groningen, The Netherlands.

ENSAR2 Town Meetinghttp://www.ensarfp7.eu/

June 4–8Matsue, Japan. 10th Interna-

tional Conference on Direct Reac-tions with Exotic Beams (DREB) 2018

http://indico2.riken.jp/indico/conferenceDisplay.py?confId=2536

June 7–12Kraków, Poland. MESON2018

15th International Workshop on Meson Physics

http://meson.if.uj.edu.pl/

August 26–September 2Zakopane, Poland. Zakopane

Conference on Nuclear Physics 2018 “Extremes of the Nuclear Land-scape”

http://zakopane2018.ifj.edu.pl/

September 2–7Bologna, Italy. EUNPC 2018http://www.eunpc2018.infn.it/

September 10–15Petrozavodsk, Russia. IX Inter-

national Symposium on Exotic Nu-clei, EXON-2018

http://exon2018.jinr.ru/

More information available in the Calendar of Events on the NuPECC website: http://www.nupecc.org/

Page 44: Nuclear Physics News - NuPECCeditorial Vol. 27, No. 3, 2017, Nuclear Physics News 319 June 2017 was a special day for NuPECC. Indeed, that day the “Long Range Plan for Nuclear Re-search

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