Status of BELEN detectorpersonal.ph.surrey.ac.uk/~phs1zp/helsinki13/belen_cortes.pdf · BELEN...
Transcript of Status of BELEN detectorpersonal.ph.surrey.ac.uk/~phs1zp/helsinki13/belen_cortes.pdf · BELEN...
NUSTAR Week - 2013, Helsinki (Finland)
(7-11 October 2013)
Status of BELEN detector
Guillem Cortes Rossell
October 11th, 2013
E-mail: [email protected]
http://greener.upc.edu/greter
BELEN detector configuration
Polyethylene shielding
Beam hole
Front view
• Energy of beta-delayed neutrons not well known
• The neutron detection efficiency must be as flat as
possible for a wide range of neutron energies
• The efficiency depends on many parameters:
• Diameter of beam hole
• Number of neutron counters
• Distance of counters to the center of polyethylene
matrix
• Number of rings
Rings of 3He proportional counters Polyethylene matrix
3-D view
Neutron detection efficiency
• Number of rings
We need to find
the optimal
configuration
MC simulations
Neutron source
Point source
Inside the beam hole
Centered in the matrix
Neutrons emitted in all directions
(isotropic distribution)
Simulation codes
MCNPX 2.5
GEANT4
Neutron energies simulated
0.0001 MeV
0.001 MeV
0.01 MeV
0.1 MeV
1 MeV
2 MeV
3 MeV
4 MeV
5 MeV
Polyethylene properties
Density: 0.95 g/cm3
HD-Polyethylene (HDPE)
CH2
MC Simulations
Parameter used to define the planarity of neutron detection efficiency
Efficiency factor, F: The relation between the maximum efficiency, ηmax,
and the minimum efficiency, ηmin ,at a defined
interval of neutron energies
max
η
η=F η1,min η1,max
minηη1,min η1,max
Neutron energy interval : 10 keV – 2 MeV
048.11.60
0.63
min,1
max,1
1 ===η
ηF
Example
Detector Name
3He counters
Pressure (atm) ExperimentRatio
@2 MeV
Ratio @
5 MeV
Mean efficiency
Beam hole radii (cm)
BELEN-20 20 20 IGISOL: Jyväskylä - 2009 --- DONE 1.17 [1.60] 27% 5.5
BELEN-20 20 20 IGISOL: Jyväskylä - 2010 --- DONE 1.17 [1.60] 35% 5.5
BELEN-30 20+10 20 & 10 GSI: Germany – 2011 --- DONE 1.17 [1.70] 40 %11.5
(SIMBA)
BELEN-48 40+8 8 & 10PTB: Germany-2013 (Detector
calibration) --- DONE1.02 1.16 45% 5.5
BELEN-48 40+8 8 & 10 IGISOL: Jyväskylä - 2014 --- Approved 1.02 1.16 45% 5.5
EXPERIMENTS WITH BELEN PROTOTYPES
3 prototypes constructed : B ELEN-20, BELEN-30 and BELEN-48
[1]
[2]
[3]
[4]
[5]
[1] Submitted (july-2013) a paper to Nuclear Inst. and Methods in Physics Research, A: M.B. Gómez et al.“Design
and commissioning of the BEta DeLayEd Neutron detector”
[2] Not yet finished data analysis. Distribution of neutron counters optimized to increase the mean efficiency.
[3] GSI: S410/S323. “Measurement of beta-delayed neutrons around 3rd r-process peak”. Data analysis will be
finished first semester 2014. Phd.Thesis Roger Caballero
[4] Measurements done on 24-28 June 2013. Preliminary experimental results agree with MC simulations
[5] The experiment “Measurement of the beta-delayed 2-neutron emitter 136Sb”is approved and scheduled for first
semester 2014. Two matrix will be used: One with a beam hole of 3 cm radii, and other with a beam hole radii of
5.5 cm to insert a HPGe detector for gamma coincidence measurements.
EXPERIMENTS WITH BELEN PROTOTYPES
B ELEN-20 B ELEN-30
Evolution of neutron detection efficiencies
B ELEN-48Beam hole 3 cm radii Beam hole 5.5 cm radii
OTHER EXPERIMENTS WITH A PROTOTYPE OF BELEN-SHAPED CONFIGURATIONS
Ring Radii (cm)Number of
counters
Pressure
(atm)
Diameter
(inch)Institute
1 12.0 10 10 2 ORNL
2 19.5 42 8 1 UPC
Example: Configuration for max. neutron energies of 3 MeV
• Design of a big BELEN detector for the measurement of beta-delayed 1-neutron and 2-
neutron emission at RIKEN (BRIKEN collaboration).
• Not yet submitted the proposal (expected april-2014)
• Measurements (if approved) at RIKEN: end of 2014 or beginning 2015
Neutron detection efficiency
2 19.5 42 8 1 UPC
3 25.0 10+13x2+15 8/5.13/4 1/1.18 GSI+RIKEN+JINR
4 30.5 22 10 2 ORNL
5 36.0 24 10 2 ORNL
149 3He
counters
Front view of the
polyethylene
matrix
CONSTRUCTION STATUS OF THE BELEN DETECTOR FOR FAIR
Equipment available
- 52 3He neutron counters: The neutron detector designed consists on 48 counters (40 from UPC and 8 from GSI) the other 4 counters are reserved for
replacement if needed. See table 1
- Matrix: (900 mm x 900 mm x 800 mm) block of high density polyethylene (density = 0.95 g/cm3) for the BELEN-48 prototype
(11 cm beam hole)
- Electronics: 2 crates, ADC’s 8 channels/ADC, shapers, HV sources, clock & pulse generator, pre-amplifiers
Equipment/material pending
- Matrix: (900 mm x 900 mm x 800 mm) block of high density polyethylene (density = 0.95 g/cm3). See table 2
- Wiring + connectors
- Supporting table
Units in mm Central holeRings
Inner Central Outer
Diameter 160 110 170 210
Holes diameter -- 27.5 27.5 27.5
Number of 3He counters at 10 atm -- 0 8 0
Number of 3He counters at 8 atm -- 10 4 26
Diameter
(cm)
Effective
Length
(inch/mm)
GSI He-3 10 2.54 600 10
UPC He-3 8 2.54 600 42
52
NUMBER OF
COUNTERS
TOTAL
INSTITUTEFILLING
GAS
PRESSURE
(atm)
DIMENSIONS
Table 1. Properties of neutron counters Table 2. Dimensions of polyethylene matrix BELEN-48
- Supporting table
CONSTRUCTION STATUS OF THE BELEN DETECTOR FOR FAIR
Front view of the detector with a
beam hole of 16 cm diameter
Neutron detection efficiency for BELEN-48
(16 cm diameter beam hole)
BELEN-48 + AIDA
To be done
- Test the possibility to modify the cross section of beam hole by a squared cross section to fit better
AIDA
- New designs to optimize he efficiency for different neutron energy ranges (optional)
- Design a table to move the detector (distance from centre of beam line to the ground needed)
- Explore the possibility to use more counters to increase the efficiency (Dubna?)
FUNDING STATUS
Research Institution Funding institution EquipmentINVESTED
(kEUR)
REMAINING
[until 2015]
(kEUR)
42 He-3 neutron counters (1) 154 (2)
Electronics + Polyethylene 111
Electronics + Polyethylene + Support structure 30
10 He-3 neutron counters + Polyethylene+Electronics 140
Polyethylene+Electronics 25
Total 301 55
TOTAL COST OF BELEN
Universitat Politècnica de Catalunya
Barcelona (Spain)
IFIC - Valencia (Spain)
356
Spain Government, Ministry of Economy
and Competitiveness, Plan Nacional de
I+D+I
Spain Government, Ministry of Economy
and Competitiveness, Plan Nacional de
I+D+I, FPA2011-28770-C03-03
GSI - Darmstadt (Germany)German Helmholtz Association via the
"Young Investigators Project VH-NG-627"
Electronics + development of software for DACQ system 50
(1) The 3He pressure of first 22 neutron counters was 20 atm.
• To increase the efficiency we needed to increase the number on neutron counters
• 2 options:
– Buy 20 new counters: Too expensive (aprox. 20 kEUR/counter )
or
– Duplicate the 21 neutron counters reducing the pressure to 8 atm and refill 21 new counters at 8 atm:
42 new counters at 8 atm (aprox. 3 kEUR/counter)
– One counter at 20 atm has been reserved for testing
(2) The price includes the cost of first 22 neutron counters and the cost related with the modification of 42
counters
MEMBERS OF THE COLLABORATION BUILDING THE DETECTOR
Research institution City and Country Members (Alphabetical order)
Universitat Politècnica de Catalunya Barcelona, Spain Roger Caballero, Francisco Calviño, Guillem Cortés(*)
, Carme Pretel, Albert Riego
Instituto de Física Corpuscular (IFIC), CSIC-Valencia, Spain
Jorge Agramunt, Alejandro Algora, César Domingo-Pardo, M. Dolores Jordan,
STATUS OF THE TDR
• The definitive version of the TDR will be submitted to the collaboration on January-2014 to be approved
Includes:
- Optimized neutron counter distribution in PE matrix (new results from prototypes)
- New 3He neutron counters at 8 atm
Instituto de Física Corpuscular (IFIC), CSIC-
Universidad de ValenciaValencia, Spain
Jorge Agramunt, Alejandro Algora, César Domingo-Pardo, M. Dolores Jordan,
Berta Rubio, José Luís Taín
CIEMAT Madrid, Spain Daniel Cano-Ott, Trino Martínez, Emilio Mendoza
GSI Darmstadt, Germany Iris Dillmann, Alexey Evdokimov, Michele Marta
(*) Spokesperson of BELEN detector