Status of the DESPEC Neutron Detection Working Group D. Cano-Ott on behalf of the WG members

CiematCentro de Investigaciones Energéticas, Medioambientales y Tecnológicas

D. Cano-Ott DESPEC/HISPEC Coll. Meeting, 15th-16th of June 2005-Valencia

Status of the DESPEC Neutron Detection Working Group

D. Cano-Ott on behalf of the WG members

CIEMAT, IFIC, LNL, FYL, UPC, UU, UW…



Motivation

GOAL: to measure neutron emission probabilities and energies for neutron rich isotopes with relevance to basic nuclear physics and nuclear technology:-Low production: 4 detector-High production: TOF spectrometer (in combination with a gamma ray setup)



Activities

Monte Carlo simulations of the 2 types TOF array (GEANT4) and the 4 detector (MCNPX) for the design of the prototypes/setups.

Hardware acquired for the prototyping phase

3 x BF3 counters3 x 3He counters1 m3 of polyethylene1 x BC501A (NE213) scintillator from St. Gobain with low background housing (5” x 5”)1 additional module from Scionix under discussion (P. Schotanus)Computer driven CAEN HV Crate2 HV cards with 10 channels each

Test measurements in the next few months

-Preparation of a test bench at CIEMAT. Calibration with -ray sources.-Calibration of the BC501A module with a D/T source in Grenoble. Validation of the simulation tools.-Monitoring of a D/D and D/T source in Minsk (YALINA experiment)-Test of digital electronics (question to DAQ) for n/ discrimination



2R

d

L

Neutron source

(I) TOF Neutron Spectrometer (NE213)(I) TOF Neutron Spectrometer (NE213)













(II) Position Sensitive TOF Neutron Spectrometer (NE213)(II) Position Sensitive TOF Neutron Spectrometer (NE213)

H

d

LNeutron source

Possible 2nd layer of

detectors for enhancing the

efficiency













First results on the TOF neutron spectrometer

The Monte Carlo simulation tools have been setup up. A realistic geometry of the detectors has been modelled for the GEANT4 code.The efficiencies and energy resolutions of the two setups are in agreement with the initial estimates. As expected, they depend on the energy thresholds.

Next steps

-Inclusion of the light quenching effect: L(Z,Edep)-Inclusion of the position sensitivity resolution and flight path reconstruction. -Careful analysis of the effect of the cross talk.-Influence of the implantation setup.



Monte Carlo Simulation of the NERO[1] 4 Neutron

Detector (BF3 – 3He)

A. Poch, G. Cortés, F. Calviño, C. Pretel

Barcelona, Spain

February 13, 2006

[1] Hendryk Schatz [email protected]://www.nscl.msu.edu/tech/devices/nero/tech.html



In this work we have studied the neutron detection efficiency for a neutron detector based on a set of BF3 and 3He proportional counters, by means of Monte Carlo simulations with MCNPX.

The neutron energy ranges from 0.1 eV to 10 MeV.

1. INTRODUCTION



2. DESCRIPTION OF THE DETECTOR

Ring A3He prop. CountersInternal diam.:2.5 cmLength: 80 cmPressure:4.1 barWall thickness:0.05 cm

Polyethylene(60cm x 60cm x 80cm)

Ring B and CBF3 prop. Counters (99% 10B)Internal diam.: 5.08 cmLength: 80 cmPressure: 0.7 barWall thickness:0.05 cm

Boron Carbide layer1 cm thickness

Hole (void)22.4 cm diameter



3. DESCRIPTION OF THE SIMULATION

Source: Isotropic point source located at the center

N=106 neutrons

Neutron energy: 0.1 eV, 1 eV, 10 eV, 100 eV, 1 keV, 10 keV, 100 keV, 1 MeV, 10 MeV

Tallies: Current integrated over a surface




nin (incident neutrons at external wall)

nout(Outgoing neutrons at internal wall)

Section of a proportional counter (BF3 or 3He)

Point source

nsource

Absorbed neutrons: nabs =n*in - nout

n*in (incident neutrons at internal wall)




Detector efficiency:abs(A,B, or C)

A,B, or Cin

n

n

Total Total,A Total,B Total,C

Detection efficiency:abs(A,B, or C)

Total,(A,B, or C)source

n

n

(Efficiency for the counters in the rings A, B or C)

(Efficiency for the counters in the rings A, B or C)

Total Detection efficiency:



4. RESULTS

Energy(eV)

Detector efficiency Detection efficiency

ηA ηB ηC ηTotal,A η,Total,B η,Total,C

ηTotal

(A+B+C)

0.1 0.238 0.332 0.331 0.280 0.130 0.035 0.444

1 0.219 0.327 0.328 0.271 0.149 0.041 0.462

10 0.197 0.316 0.321 0.253 0.168 0.049 0.470

102 0.178 0.302 0.312 0.237 0.182 0.058 0.477

103 0.161 0.284 0.297 0.221 0.192 0.067 0.481

104 0.145 0.265 0.281 0.206 0.202 0.077 0.484

105 0.125 0.228 0.249 0.182 0.211 0.096 0.489

106 0.093 0.147 0.165 0.123 0.196 0.136 0.455

107 0.048 0.071 0.084 0.035 0.082 0.084 0.201



4. RESULTS

1 x1 0 -7 1 x1 0 -5 1 x 10 -3 1 x 10 -1 1 x1 0 1

E (M eV )0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

Det

ecti

on e

ffic

ienc

y

R in g A (3H e), hT ota l,A

R in g B (B F 3) , hT ota l,B

R in g C (B F 3) , hT ota l,C

T o ta l (A + B + C ), hT o ta l

1 x1 0 -7 1 x1 0 -5 1 x1 0 -3 1 x1 0 -1 1 x1 0 1

E (M eV )0

0 .1

0 .2

0 .3

0 .4

0 .5

0 .6

Det

ecto

r ef

fici

ency

R in g A (3H e), hA

R in g B (B F 3) , hB

R in g C (B F 3) , hC



First results on the 4 detector

The first Monte Carlo simulation of the 4 detector has been completed. The efficiency of the detectors is compatible (according to the information available) to the available about NERO.

Next steps

-Refinement of the “tallies” (MCNPX output) and calculation of the efficiency.+-Validation of the Monte Carlo results with experimental data.-Effect of the implantation setup.-Investigation of alternative geometries + algorithms for a “possible” energy reconstruction (deconvolution)

Documents

Status of the DESPEC Neutron Detection Working Group D. Cano-Ott on behalf of the WG members