BRIKEN: a high-efficiencydetector for β-delayed …€¦ · Belen Gomez UPC Post-doc...

[DETECTOR CONSTRUCTION PROPOSAL]

BRIKEN:

a high-efficiency detector for β-delayed

neutron measurements at RIKEN

C. Domingo-Pardo, BRIKEN Construction Proposal, NP-PAC, RIKEN Nishina Center 13-14/12/2013

Introduction: the BRIKEN project

• BRIKEN stands for Beta delayed neutron measurements at RIKEN.

• BRIKEN was born as a scientific need of nuclear data (half-lives and neutron branchings) for:

– Astrophysics

– Nuclear structure

– New reactor technologies

• BRIKEN aims at:

– most exotic nuclei � RIKEN BigRIPS

Open project; to join send

an email to:

[email protected]

– most exotic nuclei � RIKEN BigRIPS

– largest detection sensitivity � large neutron detector array (Large Collaboration)

� 1st BRIKEN Workshop @ Valencia, Spain 17-18/12/2012

(http://indico.ific.uv.es/indico/event/briken)

� 2nd BRIKEN Workshop @ RIKEN Nishina Center, 30-31/07/2013

(http://indico.ific.uv.es/indico/event/briken2)

Aim: Bring together the nuclear structure, astrophysics and reactor technology

communities in order to discuss the experimental setup and physics campaign for relevant

b-n experiments at the RIBF of RIKEN


Presenter Topic Nuclei

S.Nishimura

(RIKEN)

Below the 2nd r-process

peak 112Zr-129Pd

F. Montes (MSU) 2nd r-process peak 139Sb

C.Domingo (IFIC) Rare-earth r-process peak 151La-173Tb

G. Lorusso

(RIKEN) 2nd r-process peak 129Ag-142Te, 133-134Cd

M.Marta

I.Dillmann

(GSI/RIUMF) Multiple n emission 76Co-81Cu, 134Sn-133Cd

BRIKEN Physics Goals for a Project Proposal in 2014

Astrophysics:

r-process

nucleosynthesis

Nuclear

PROJECT

PROPOSAL

(GSI/RIUMF) Multiple n emission 76Co-81Cu, 134Sn-133Cd

K.Rykaczewski

(ORNL)

One and two n emiiters

above 78Ni and 132Sn Ni, Cu ,Zn, Ga, Ge, As, Se, In

R.Griwacz

(U.Tennessee)

One and two n-emission

below and at 78Ni

Cl, Ar, K, Ca, Sc, Ti, Ni, Cu, Zn,

Mn, Fe, Co

A Algora Deformation A~110 106-110Zr, 110-114Mo

B. Rubio (IFIC) Nuclear structure ~132Sn 130Ag-138Sb

A.Estrade

(Edinburgh) Masses Several

J.L. Tain (IFIC) β-strength NE of 78Ni 85Ge-97Br

D.Cano-Ott

(CIEMAT) Reactor technologies

Ge86,Rb-96,Rb100, Y98m,

Cd131, Sb137

Nuclear

Structure:

1n, 2n-

competition

in heavy

nuclei, FF vs.

GT, etc

New reactor

technologies

BRIKEN: Experimental Setup

BRIKEN neutron

detection set-up

Advanced

Implantation

Detection

Array• 10 pnA 238U @ 345 MeV/u


AIDA: Advanced Implantation Detection Array @ RIKEN

Advanced

Implantation

Detection

Array

Implant – decay correlations

• Multi-GeV implantation events

• Subsequent low-energy decays

• Tag events for gamma and neutron detector arrays

• 12x 8cm x 8cm DSSSDs

24x AIDA FEE cards

• 3072 channels

• Tag events for gamma and neutron detector arrays

Detector: multi-plane Si DSSD array

wafer thickness 1mm

8cm x 8cm (128x128 strips)

Instrumentation: ASIC

low noise (<12keV FWHM)

low threshold (0.25% FSR)

20GeV FSR plus ( 20MeV FSR or 1GeV FSR)

fast overload recovery (~ms)

spectroscopy performance

time-stamping

In-beam test @ GSI 250 MeV/u 209Bi SIS beam (2011)


BRIKEN neutron detector array

n + 3He →→→→ 3H + 1H + 0.764 MeV(abund.=0.00014%)

γ-quanta

wall-effect

full-energypeak

High selectivity of 3HeNeutron detection principle:

High efficiency using counters embedded in a high-density polyethylene matrix:


Institute Pressure Diameter Length # Tubes

GSI 10 1 600 10

JINR 4 1.18 500 20

ORNL 10 2 609.6 67


• Despite the shortage in 3He, we have managed to gather a very large number of 3He

counters thanks to a joint international effort (BRIKEN Collaboration), which will make this

instrumentation available for a campaign of measurements at RIKEN.

• How to make the best possible use of such a large amount of neutron detectors?

�Maximise efficiency to measure weak emission rates, two-fold neutron emission, etc.

� Constant efficiency as a function of the neutron energy, to avoid systematic effects

related to the neutron energy spectrum.

ORNL 10 1 609.6 17

RIKEN 5.13 1 300 26

UPC 8 1 600 42

Total 182


Analysis of ring radii for 1” diameter counters at 8 atm


11 cm radius

30 cm radius

radius

- Single ring filled with 3He counters at 8 atm and 1’’ diameter- Ring radii variation from 11 cm to 30 cm

Analysis of ring radii for 1” diameter counters at 8 atm


174 3He tubes of 6 different types:


Ring Radius

(cm)

# 3He

Tubes

Pressure

(atm)

Diameter

(inch)

Institute

1 9.4 14 10 1 ORNL

2 13 12+12 5.13 1 RIKEN

3 16.8 10+26 10/8 1 GSI/UPC

4 20 18+18 5/8 1.18/1 JINR/UPC

5 27 26 10 2 ORNL

6 35 38 10 2 ORNL

174 He tubes of 6 different types:

• High average efficiency of > 60 %

• Flat efficiency 6% up to 4 MeV, 12% up to 5 MeV.


F100eVEn = εmax/εmin

Flat efficiency � Pn insensitive to neutron spectrum

High efficiency also for two-fold neutron emission:



Two Neutron Detection

High efficiency also for two-fold neutron emission:Ring Radius

(cm)

# 3He

Tubes

Pressure

(atm)

Diameter

(inch)

Institute

1 9.4 14 10 1 ORNL

2 13 12+12 5.13 1 RIKEN

3 16.8 10+26 10/8 1 GSI/UPC

4 20 18+18 5/8 1.18/1 JINR/UPC

5 27 26 10 2 ORNL

6 35 38 10 2 ORNL

174 He tubes of 6 different types:

• High average efficiency of > 60 %

• Flat efficiency 6% up to 4 MeV, 12% up to 5 MeV.


Beam view Side view

BRIKEN hybrid neutron detector array

# 3He Tubes Pressure

(atm)

Diameter

(inch)

Institute

42 8 1 UPC

10 10 1 GSI

16 12 2 ORNL

56 10 2 ONRL

24 5.13 1 RIKEN

20 5 1.18 JINR

� εn(500 keV) = 75.6%

� εn (2.5 MeV) = 66.5%

�εγ (1 MeV) = 3 %

• Level structure of daughter nuclei by

gating on the neutrons.

• Key performance features:



BRIKEN CollaborationAgnieszka Korgul University of Warsaw Researcher [email protected] UPC Researcher [email protected] Estrade University of Edinburgh Post-doc [email protected] Algora IFIC Researcher [email protected] Kankainen University of Edinburgh Post-doc [email protected] Garnsworthy TRIUMF Researcher [email protected] Gomez UPC Post-doc [email protected] Rubio IFIC Professor [email protected] Calvino UPC Professor [email protected] Domingo Pardo IFIC Researcher [email protected] Mazzocchi University of Warsaw Researcher [email protected] Griffin University of Edinburgh PhD-Student [email protected] Lederer University of Edinburgh Post-doc [email protected] LSU Post-doc [email protected] Cano Ott CIEMAT Researcher [email protected] Cano Ott CIEMAT Researcher [email protected] Dolores Jordan IFIC Post-doc [email protected] Joss University of LIverpool Researcher [email protected] Lorusso RIKEN Post-doc [email protected] J. Gross ORNL Researcher [email protected] Cortes UPC Researcher [email protected] Gyorgy ATOMKI Researcher [email protected] Sakurai The University of Tokyo Professor [email protected]. Ueno RIKEN Professor [email protected] Dillmann TRIUMF Researcher [email protected] Simpson Daresbury Laboratory Researcher [email protected] Agramunt IFIC PhD-Student [email protected] Gabor ATOMKI Researcher [email protected] Kolos University of Tennessee Researcher [email protected]. Miernik University of Warsaw Researcher [email protected] P. Rykaczewski ORNL Researcher [email protected] Smith University of Notre Dame PhD student [email protected] Gyula Kiss ATOMKI Researcher [email protected]. Domingo-Pardo, BRIKEN Construction Proposal, NP-PAC, RIKEN Nishina Center 13-14/12/2013

BRIKEN CollaborationToshiuki Kubo RIKEN Researcher [email protected] Labiche Daresbury Laboratory Researcher [email protected] Matsui University of Tokyo PhD student [email protected] Niikura University of Tokyo Professor [email protected] Marta GSI Post-doc [email protected] Madurga University of Tennessee Post-doc [email protected] Montes NSCL Researcher [email protected] Brewer University of Tennessee Post-doc [email protected] Nishimura RIKEN Researcher [email protected] Kobayashi University of Tokyo Post-doc [email protected] Pereira Conca NSCL Researcher [email protected] University of Guelph Professor [email protected] J. Woods University of Edinburgh Professor [email protected] Grzywacz University of Tennessee Professor [email protected] Page University of Liverpool Professor [email protected] Page University of Liverpool Professor [email protected] Caballero Folch UPC PhD student [email protected] Taniuchi The University of Tokyo PhD student [email protected] Rinta Antilla University of Jyvaskyla Researcher [email protected] Momiyama University of Tokyo Student [email protected] Sokol JINR Researcher [email protected] Davinson University of Edinburgh Researcher [email protected] Luis Tain IFIC Researcher [email protected] Miyazaki University of Tokyo Student [email protected] Martinez CIEMAT Post-doc [email protected] Schatz MSU/NSCL Professor [email protected] Ma RIKEN Researcher [email protected] Xu University of Tokyo PhD student [email protected] Liu IMPCAS Researcher [email protected] A. Winger Mississippi State Univ. Researcher [email protected]. Wolinska Cichocka ORNL Post-doc [email protected] Wu Peking University PhD student [email protected] Fulop ATOMKI Researcher [email protected]. Domingo-Pardo, BRIKEN Construction Proposal, NP-PAC, RIKEN Nishina Center 13-14/12/2013

BRIKEN Collaboration


[email protected]

http://indico.ific.uv.es/indico/event/brikenhttp://indico.ific.uv.es/indico/event/briken2

BRIKEN: Summary & Conclusions

• Beta-delayed neutron branching ratios and half-lives are of relevance for

astrophysics, nuclear structure and new reactor technologies.

• We propose to build a very large neutron detector array (BRIKEN) based on 174 3He

tubes (readily available from the BRIKEN collaboration) for beta-delayed neutron

emission measurements at the RIKEN.

• The Advanced Implantation Detector Array AIDA will be used to detect with high• The Advanced Implantation Detector Array AIDA will be used to detect with high

precission both implant- and decay-events and to determine half-lives.

• Test (integration) with AIDA and (a part of) BRIKEN neutron detector in 2014 at RIKEN

either F11 or F12.

• Proposals to be submitted under the same umbrella as a “Project Proposal” for the

next PAC in 2014.

• The project is open, new collaborators are welcome to join!


Backup Slides

Background MeasurementsBackground Measurements

BACKGROUND EVENTS

ARTEFACTS

Average 1-2

Counts/min

Monte Carlo calculations forcalculations for

BRIKEN Geometry

Monte Carlo simulations of BRIKEN detector configurations

C. Domingo-Pardo, M.D. Jordan, J.L. TainInstituto de Fisica Corpuscular, Valencia, Spain

• Simulation framework• Some preliminary facts• Some preliminary facts• Geometries without clovers• Geometries with clovers• Reliability of simulations• Shielding• βnγ coincidences• Conclusions

Second BRIKEN Workshop, RIKEN, July 29-30, 2013

• Simulation codes:• Geant4 version 9.4.p02, neutron data file:

ENDF/B7.0*, thermal scattering data for H in PE• Slightly different results than G4NDL3.14• Uncorrected bug found by A. Garcia (CIEMAT)

• MCNPX version 26.d, neuntron data file ENDF/B6.1

• PE density = 0.95g/cm3 (measured)• 3He active volume inside a vacuum mother volume

* Mendoza et al. (CIEMAT), http://www-nds.iaea.org/geant4/

• 3He active volume inside a vacuum mother volume but no additional materials

Fact: efficiency does not scale linearly with volume or pressure

Fact: the efficiency is altered significantly

3H tracks

n-captures mainly on outer shells

Some facts:

altered significantly by the proximity of other tubes both through removal of neutrons and decrease in moderation

Fact: large efficiency is in conflict with flat efficiency. Here we concentrate in large efficiency.

1st approach: an automatic procedure to optimize the the distance between tubes in order to maximize efficiency

Example for 100 UPC tubes: optimal spacing about 5mm

However due to geometrical constraints and the different tube dimensions it was decided to take a

2nd approach: systematic variations based on educated guesses

What maximum efficiencies should one expect?

UPC

ORNLl

UPC+ORNLl

UPC: 39GSI: 10ORNLs: 16ORNLl: 54RIKEN: 26Eff(0.5MeV)=81.5%Eff(2.5MeV)=67.3%Ratio=0.83

UPC: 42

Two reasonable configurations without CLOVERS:

R(cm): 10.5, 14.0, 17.5, 22.5, 28.5Ndet: 20, 26, 32, 24, 30

R(hole): 8cm

UPC: 42GSI: 10ORNLs: 16ORNLl: 56RIKEN: 26JINR: 3Eff(0.5MeV)=84.4%Eff(2.5MeV)=73.0%Ratio=0.86

Increasing PE from 90cm x 90cm x 90cm to 90cm x 90cm x 140cm does not change significantly the efficiency

R(cm): 8.0, 11.5, 15.0, 20.0, 26.0Ndet: 20, 28, 36, 24, 32

R(hole): 5.5cm


PE: 90cm x 90cm x 90cm

A reasonable configuration with 2 CLOVERS:


2 EXOGAM1 Cloversγ-effic. @1MeV = 3%

UPC: 42GSI: 10ORNLs: 16ORNLl: 48RIKEN: 24Eff(0.5MeV)=71.7%Eff(2.5MeV)=61.3%Ratio=0.85

Another configuration with 2 CLOVERS:


PE: 90cm x 90cm x (70+45)cm

Another configuration with 2 CLOVERS:

PE: 90cm x 90cm x (70+45)cm

• AIDA is designed to fit a PE block of up to 45-50cm half-length

• Possible problem: location of cables/length of cables

A configuration with 4 CLOVERS:


Evolution of the efficiency with energy:

Log-E scale Lin-E scale

(incomplete)

The effect of an extended source is marginal:• Comparing a point source with a 8cm x 8cm x 8cm

source:81.5% -> 81.7% @ 0.5MeV67.3% -> 67.5% @ 2.5MeV

Up to 8 DSSSDs8cmx8cm∆z=1cm

AIDA

NOTE: it is not clear how the inclusion of ancillary detectors (AIDA, CLOVERS) affect the reliability of MC predictions.• Experimentally SIMBA decreased efficiency by 3% for

252Cf

Simulations performed with MCNPX gave very similar results:• For example, G4: 81.3%/68.0%, MCNPX: 81.2%/66.9%

How reliable are MC simulations?BELEN-20a Efficiency

Isotope

Mean

E Exper. MCNPX G4 G4 (bug)

94Rb 437 0.302(8) 0.298 0.300 0.319

95Rb 525 0.301(16) 0.296 0.298 0.317

BELEN-20b Inn/out ratio

Isotope Mean E Exper. MCNPX G4 G4 (bug)

88Br 247 3.04(2) 3.27 3.32 3.25

BELEN-20a BELEN-20b

BELEN-30

252Cf

88Br 247 3.04(2) 3.27 3.32 3.25

94Rb 437 2.51(2) 2.66 2.71 2.66

95Rb 525 2.52(3) 2.62 2.63 2.60

137I 625 2.20(2) 2.22 2.24 2.21

252Cf 2200 1.50(1) 1.56 1.57 1.56

BELEN-30 Efficiency Inn/out ratio

Isotope Mean E Exper. MCNPX G4 G4 (bug) Exper. MCNPX G4 G4 (bug)

252Cf 2200 0.351(8) 0.348 0.350 0.363 0.726 0.758 0.764 0.756

BELEN-48: New measurement at PTB (Dillmann/Marta)

Shielding:

BELEN-20b @ JYFL-IGISOL

Beam-off: 0.7 cpsBeam-on: 0.9 cpsMC = 2 cps

MC = 5.7 cps

Simulation with ambient background shape and Φ=5E-3 cm-2s-1Ambient background

Beam induced background: 260 n/s (Secondary) beam

BRIKEN geometry:

Beam induced background:

BELEN-30 @ GSI-FRS

Cou

nts

1.5 n/s

On-spill

Off-spill

1s + 2s

BELEN

Forward Neutron shield

(Secondary) beam induced background depends on settings and devicesContribution to beta-n correlations:250 cps � 0.12 counts in 500 µsmoderation time � equival. to

Should be reduced by passive shielding and active vetoing

Results from JFYL 2010 BELEN-20b experiment:

Small CloverDistance 5.5cm:Effic(200keV)=4.5%Effic(1MeV)=1.4%

Sensitivity of the setup to ββββnγγγγ branches

n-effic. = 50%β-effic. = 24%

0.3%

β-effic. = 24%γ-effic. :

Effective rate=310 ppsTmeas= 3.3h

Iγ(213KeV)=0.82% I (432keV)=1.13%

Iγγγγ !?

Pn=10.2%

γIγ(432keV)=1.13%Iγ(986keV)=0.54%

Background subtracted

213432 986?

Nβn(213KeV)=30 Nβn(432keV)=17Nβn(986keV)=?

(expec. 7)

836X

X

Effective rate=110 ppsTmeas= 2.2hIγ(836keV)=2.83%Nβn= 17 counts

Effective rate=435 ppsTmeas= 4.2h

Iγγγγ !?

Pn=8.7%

Pn=6.4%

532

Tmeas= 4.2hIγ(532keV)=0.28%Nβn=10 counts

At RIKEN:β-effic=50%n-effic=70%γ-effic=5%

βnγ-effic=1.75%

Counts=implant-rate x time x γ-branch x βnγ-efficiency

For 1 pps in 1 day we would collect 15 counts for a 1% γ-branch

Conclusions:• Without CLOVERS:

• Efficiencies (in the flat region): 80-85%• Ratio (2.5MeV/0.5MeV ): 0.83-0.86

• With 2 CLOVERS:• Efficiencies of the order of 70-75% • Ratio: 0.84-0.88

• With 4 CLOVERS:• With 4 CLOVERS:• Efficiencies: 58% • Ratio: 0.89

UPC: 42GSI: 10RIKEN: 26JINR: 20Eff(0.5MeV)=73.4%Eff(2.5MeV)=56.0%Ratio=0.76


Other possibilities:UPC: 42GSI: 10ORNLs: 16ORNLl: 56RIKEN: 24Eff(0.5MeV)=75.3%Eff(2.5MeV)=64.9%Ratio=0.86

CurrentCurrent status of BRIKEN, status of BRIKEN, what’swhat’s new?new?

Effi

cien

cy (

%)

500 keV2.5 MeV

BRIKEN-Detector: Efficiency for (ββββ,n), (ββββ,2n) and (ββββ,3n)

BRIKEN: an excellent place to measure multiple neutron emitters!

Effi

cien

cy (

%)

1 n 2 n 3 n

CurrentCurrent status of BRIKEN, status of BRIKEN, what’swhat’s new?new?

BRIKEN: a high performance also for gamma-neutron correlations!

72% 62%

neutron

γγγγ n-γγγγ

2.8% 2%

BELEN design in progress for RIKEN with AIDA

48 tubes

Optimized for range 100 keV – 5 MeV

Radius 8 cm

BELEN design in progress for RIKEN with AIDA

48 tubes

Optimized for range 100 keV – 1 MeV

Radius 8 cm

BELEN design in progress for RIKEN with AIDA (8cm central hole)

Previous versions New designsConcept Detection System New designs

1 MeV

30

5 MeV

AIDAAIDA

8 cm * 8 cm AIDA compact system

• 12x 8cm x 8cm DSSSDs24x AIDA FEE cards

• 3072 channels

- Design drawings (PDF) availablehttp://www.eng.dl.ac.uk/secure/np-work/AIDA/

Bench test system for individual AIDA cards

Mezzanine:4x 16 channel ASICsCu coverEMI/RFI/light screencooling

FEE:4x 16-bit ADC MUX readout (not visible)8x octal 50MSPS 14-bit ADCsXilinx Virtex 5 FPGAPowerPC 40x CPU core/Linux OS – DAQ

Gbit ethernet, clock, JTAG portsPower

FEE width: 8cmPrototype – air coolingProduction – recirculating coolant

Pulser tests of AIDA Hardware performance

INL < 0.1% ( > 95% FSR )

Tests with pulser demonstrating integral non-linearity and noiseperformance of 20MeV range

0.15mV rms ~ 2.5keV rms Si

All production hardware (ASIC, FEE Mezzanine PCB, FEE PCB) delivered by sub-contractors

Initial conversion e- measurements with AIDA system

• Realistic input loading CD ~ 60pF, IL ~ 60nA• Expect to achieve full design resolution ~12keV FWHMand low energy threshold ~50 keV

GSI Commissioning Test – August 2011

• SIS 250MeV/u 209Bi

• Beam delivery direct to Cave C

• From exit port+ ~1.0m air+ ~2mm Al (degrader)+ ~0.9m air+ 1x MSL type W-1000 DSSSD

cheap alternative to type BB18 …

• Test of response of 20GeV range

• No rejection of lighter, lower energy ions generated by passage ofbeam through exit port/degrader

Data Acquisition System

Hardware availability and costs

Hardware Institution Availabilityin 2014/15?

Shipment Co. Cost(Euros)

3He tubes ORNL Yes3He tubes UPC Yes TECNISAMPLE 20003He tubes JINR Yes3He tubes RIKEN Yes N.A. N.A.3He tubes GSI Yes

PE-Matrix GSI/Triumf Yes 2600

AIDA Edinburgh, Liverpool, Daresbury, etc

Yes

DDAS IFIC Yes TNT 4000

LoIs for Experiments @ BRIKEN


S.Nishimura 2nd r-processpeak

A=110-125112Zr-129Pd

F. Montes 2nd r-processpeak

139Sb, 140Sn

C.Domingo Rare EarthPeak

151La-173Tb

M.MartaI.Dillmann

Multiple n’s,2n, 3n

78Ni (76Co-81Cu)132Sn(134Sn-133Cd)

K.Rykaczewski Multiple n 78Ni-81GaK.Rykaczewski Multiple n 78Ni-81Ga81Cu-85Se82Cu-86Se84Zn-87Se

134,135In

R.Griwacz Multiple n 48Cl-64V67Cr-69Fe74Co-77Zn76Co-79Zn

G. Lorusso 2nd r-process 129Ag-142Te133-134CdPd-chainIn-chain


A. Algora Nucl. shapes 106Zr-114Mo

B. Rubio TAS+Neutrons N>82130Ag-138Sb

A. Estrade MBRIKEN Several

J.L. Tain B-strengthfunction

85Ge-97Br

function

D.Cano-Ott Reactortechnologies

Ge86-As86Rb-96-Rb100, Y98m, Cd131, Sb137

BRIKEN: a high-efficiencydetector for β-delayed …€¦ · Belen Gomez UPC Post-doc...

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