ISOLDE – High-lights and HIE-ISOLDE
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Transcript of ISOLDE – High-lights and HIE-ISOLDE
Maria J. G. Borge , CERN, PH-Dept
Exploring the Nuclear Landscape
Maria J. G. BorgeISOLDE-PH, CERN(Isotope Separator On-Line)IEM-CSIC, Madrid
ISOLDE – High-lights and HIE-ISOLDE
19921998
HIE-ISOLDE
ISOLDE
2008
Hot Topics in Nuclear Physics
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Physics at the Femtometer scale
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Open Questions in Nuclear Physics
Observables:Ground-state properties: mass, radius, J, μ, Q momentsHalf-lives and decay modesTransition probabilitiesCross sections
Main models:Shell model (magic numbers)Mean-field models (deformations)Ab-initio approaches (light nuclei)
How are complex nuclei built from their basic constituents? strong interaction in nuclear medium • How to explain collective properties from individual nucleon behavior? collective versus individual • How do regular and simple patterns emerge in the structure of complex nuclei? symmetries
LRP2010
Production of Radiactive Beams @ ISOL Facilities
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ISOLDE Facility
intensity (2uA -> 6uA ) energy (1.4 -> 2GeV)
ISOLDE is the CERN radioactive beam facilityNuclei produced via reactions of high intensity high energy proton beam with thick and heavy targetsProvides low energy or post-accelerated exotic beams
PSB upgrade (2018)
ISOLDE at CERN
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LHC
Produced Nuclei: ISOLDE 45 y Experience
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Over 20 target materials and ionizers, depending on beam of interest operated at high temperatureU, Ta, Zr, Y, Ti, Si, …3 types of Ion-sources: Surface, Plasma, Laser> 700 nuclides of over 70 chemical elements produced
Target
ISOLDE today offers the largest range of available isotopes of any ISOL facility worldwide.
ISOLDE Physics TopicsMany beamsGood beam purity and quality
Best in the World!High intensity
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Nuclear PhysicsNuclear Decay Spectroscopy
and ReactionsStructure of Nuclei
Exotic Decay Modes
Atomic PhysicsLaser Spectroscopy and
Direct Mass Measurements
Radii, Moments, Nuclear Binding Energies
Nuclear Astrophysics
Dedicated Nuclear Decay/Reaction Studies
Element Synthesis, Solar Processes
f(N,Z)
Fundamental PhysicsDirect Mass Measurements,
Dedicated Decay Studies - WICKM unitarity tests, search for b-n correlations, right-handed
currents
Applied PhysicsCondensed matter physics and
Life sciences Tailored Isotopes for
Diagnosis and Therapy MEDICIS Project
Determination of the atomic properties of Astatine
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16150 16200 16250 16300 16350
0
10
20
30
ion
curr
ent
(pA
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wavenumber (cm-1)
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Determination of ionising potentialIdentification of new atomic transitionsComparison with atomic theoryScan of ionizing laser: converging Rydberg levels allow precise determination of the IP
IP(At) = 9.31751(8) eVNature Com. 14May2013DOI 10.1038
M. Seliverstov, V. Fedoseev team
ISOLDE collaborates with the Short-Lived Nuclei Laboratory which is based on the ISOL facility IRIS at PNPI since 1999.
Experimental hall
Target stationsHRS & GPS
Mass-sep.HRS
ISCOOLRILISREX-ISOLDE
PS-Booster 1.4 GeV protons
3×1013 ppp
ISOLTRAP
CRIS
COLLAPS
NICOLE
MINIBALL and T-REX
WITCH
Travelling setups
Travelling setups
Post-accelerated beams
Collection points
TAS
Decay spectroscopyCoulomb excitationTransfer reactionsLaser spectroscopyBeta-NMRPenning trapsApplications: Solide state Life Science
Beams of 30-60 keVBeams of 3 MeV/u
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COLLAPS – Ne charge radiiLaser spectroscopy & Massses
Geithner et al, PRL 101, 252502 (‘08)Marinova et al, PRC84, 034313 (‘11)
Intrinsic density distributions of dominant proton FMD configurations
ISOLTRAP: High-precision mass of 82Zn
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Nuclear structure: N=50 shell closure
Astrophysics: r-process path
Astrophysics: neutron star structure
Combined ISOLDE technical know-how: neutron-converter, quartz transfer line, laser ionisation
Its determination is important for modelling of the crust of neutron stars , PRL110 (2013) 04110
Bmq
c n
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CERN Courier, 53, n 3, 2013 D. Rodriguez, U. Granada
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The Magic Number N=32
Nature 498 (2013) 346
WITCH
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M. Beck et al., Eur. Phys. J. A47 (2011) 45M. Tandecki et al., NIM A629 (2011) 396S. Van Gorp et al., NIM A638 (2011) 192
June 2011 data
Energy spectrum of recoiling ions with a retardation spectrometer Use a Penning trap to create a small, cold ion bunch
Weak Interaction Trap for Charged particles -> fundamental studiesGoal: determine bn correlation for 35Ar with (a/a)stat 0.5 %
REX-ISOLDE
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Total efficiency : 1 -10 % 1+ to A/Q = 3 – 4.5Tested A/q = 2
Halo Nuclei & Reactions
1Hn
2H
3He 4He
6Li 7Li 8Li 9Li 10Li 11Li
Common “Structural” properties Rather inert core plus one or two barely
unbound extra neutrons Extended neutron distribution, large
“radius”. “halo” Very few excited states –if any.
Reaction properties at near-barrier energies:Is the Optical Model able to describe the scattering of the halo systems ? Strong absorption in elastic channel Large cross section for fragmentation They are easily polarizable.
Reaction mechanisms and Nuclear effects
of halo nuclei need to be understood
6He
Dobrovolsky et al, NPA766 (2006) 1
7Be 8Be 9Be10Be 12Be11Be 14Be
2n-halo
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Elastic scattering of halo nuclei near the Coulomb barrier
10Be+64Zn11Be+64Zn
10,11Be+64Zn
CDCC calculations
Experimental elastic cross section. reproduced only taking into account
coupling to continuum via the Coulomb and nuclear interactions
Di Pietro et al. Phys. Rev. Lett. 105,022701(2010) Catania, IEM-CSIC, Huleva, Sevilla Collaboration
Scattering of 11,9Li on 208Pb around the Coulomb Barrier
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Elastic Scattering
Scattering process dominated by:- Dipole couplings (coulomb + nuclear)- Coupling to continuum- Good description in a 4-body model Cubero et al, PRL109 (2012) 262701IEM-CSIC, Huelva, Seville Collaboration
9Li
9Li
11Li
11Li
Competing process with Elastic Scattering for loosely bound systems
ECM = 23.1 MeV below Coulomb Barrier
ECM = 28.3 MeV @ the Coulomb Barrier
Direct Breakup 2n-Transfer
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Why to study the N=Z 72Kr Nucleus?
rp-process in N=Z nuclei & A=70-80 region
Nuclear structure:o Shape coexistence in the mass region was first proposed for 72Se [Ham74].o 72Kr ground state is predicted to be oblate [Dic72] and [Naz85].o First excited 0+ state in 72Kr found to be a shape isomer [Bou03].o Possibility of study np-pairing effects as 72Kr belongs to N=Z line.
[Ham74] J.H. Hamilton et al., Phys. Rev. Lett. 32, 239 (1974)[Dic72] F. Dickmann et al., Phys.Lett. 38B, 207 (1972)[Naz85] W. Nazarewicz et al., Nucl. Phys. A435, 397 (1985)[Bou03] E. Bouchez et al., Phys. Rev. Lett. 90, 082502 (2003)
Nuclear astrophysics:o 72Kr “waiting point" in rp process.
73Rb is unbound
o β decay competes with 2p capture.
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Coulomb excitation of 72Kr
Oblate 72Kr expected
The technique
Coulex Spectra - number of counts in 710 keV peak depends on the shape of 72Kr
Doppler Corrected for 104Pd target excitation
Doppler Corrected for 72Kr projectile excitation: 150 counts in 710 keV line
Use of submicron Y203 material for target => Yield increase x 10
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TAGS @ISOLDE: The case of 72Kr
Briz, ISOLDE Workshop 2012
o Conversion electron studies to determine the multiplicities of the low gamma transitions
The B(GT) distribution favours oblate deformation!
P. Sarriguren, Phys. Rev. C 79, 044315 (2009)
o B(GT) obtained by measuring the intensity of the full gamma de-excitation cascade from each fed level to the ground state.
IEM-CSIC, Strasbourg, Surrey, Valencia
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Octupole correlations enhanced at numbers: Z or N=34, 56, 88, andN= 134. Observed Z≈88 & N≈134
Microscopically driven...
Intruder orbitals of opposite parity and ∆J, ∆L = 3 close to the Fermi level
Coulomb excitation to directly access E3 transition strengths
B(E3) 30 s.p.u. gives significant ≳β3
Searching for pear-shaped nuclei at ISOLDE
λ = 2
λ = 2
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L. P. Gaffney, et al. (2013). Nature, 497(7448), 199–204. doi:10.1038/nature12073Hangout with CERN: Going pear-shaped (http://www.youtube.com/watch?v=x8Jdu9O2RhU&feature=em-uploademail) MORE than 1000 viewers
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Physics program @ REX
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20 40 50 82184,186,188HgProbing shape coexistence
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70Se, shape coexistence, Hurst PRL 200796Sr, 88Kr, 92Kr
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122,124,126Cd138,140,142,144Xe140,148,150Ba
110Sn; Cederkäll, PRL 2007106,108Sn, Cederkäll, PRL 2008
Evolution of collectivity around 132 Sn
67,69,71,73Cu, Stefanescu et al., PRL 200868,70Cu, isomeric 68Cu, Stefanescu , PRL 2007
74,76,78,80Zn Probing large scale shell model, Van der Walle, PRL2007
30,31,32Mg, Niedermaier PRL2005, H. Scheitd(30Mg,p)31Mg, K. Wimmer, PRL 2010
REX-ISOLDE started in 200172 different beams already used at REX- ISOLDE of 700 available!
Halos & clustersd(8Li,p)9Li*; d(9Li,p)10Li…
The Limitations of REX-ISOLDE (E 3.1 MeV/u) Very limited energy flexibility Operation restricted to pulsed mode Bunch length is not flexible Extension to higher energy is difficult
222,224Ra; 220,222RnProbing Pear ShapeNature 497 (2013)199
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Near Future: HIE-ISOLDE projectEnergy Upgrade:The HIE-ISOLDE project construction of the SC LINAC to upgrade the energy of the post-accelerated radioactive ion beams to 5.5 MeV/u in 2015 and 10 MeV/u by 2017
Intensity Upgrade:The design study for the intensity upgrade, also part of HIE-ISOLDE, started in 2011, and addresses the technical feasibility and cost estimate for operating the facility at 10 kW once LINAC4 and PS Booster are online.
• Approved Dec 2009• Offically started Jan 2010• Yacine Kadi project Leader• Budget 40 M$
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Physics addressed with HIE-ISOLDE / IS564Study of the unbound proton-rich nucleus 21Al with resonance elastic and inelastic scattering using an active target (USC, IEM, MAYA Collaboration)
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ExperimentTo measure resonant elastic, 20Mg(0+), and inelastic, 20Mg(2+), scattering using MAYA to determine energy, spin and parity of the 21Al excited states.
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Summary and outlookThe future of ISOLDE is bright. It will restart in June 2014 with the low energy program.
With more than 40 year of operation ISOLDE remains as the pioneer ISOL-installation both at the level of designing new devices and production of frontier Physics.
Post accelerated beams up to 5.5 MeV/u for the wide range of nuclei produced at ISOLDE will be available from Autumn 2015.
HIE-ISOLDE will be the only next-generation radioactive beam facility (as identified by the NuPECC LRP) available in Europe in 2015, and the most advanced ISOL facility world-wide.
Welcome to propose challenging experiments!
Thanks for your attention !