NUSTAR Annual Meeting - 2014, GSI (Darmstad- Germany)

(3-7 March 2014)

Update BELEN detectorUniversitat Politècnica de Catalunya, Barcelona, Spain

F. Calviño, G. Cortès, A. Riego, R. Caballero-Folch, C. Pretel, Ll. Batet, A. Torner, A. Poch, M.B.

Gómez-Hornillos, V. Gorlychev

Instituto de Física Corpuscular, CSIC, Universidad Politécnica de Valencia, Valencia, Spain

J.L. Taín, J.Agramunt, A. Algora, C. Domingo-Pardo

Guillem Cortes-Rossell

March 4th, 2014

E-mail: guillem.cortes@upc.edu

http://greener.upc.edu/greter

GSI, Darmstadt, Germany

I.Dillmann, M. Marta

CIEMAT, Madrid, Spain

D. Cano-Ott, T. Martínez, A. garcía

BELEN detector

BEta-deLayEd Neutron detector: 4π neutron detector based on 3He counters

embedded in a polyethylene matrix

Measurement of beta-delayed neutron emission probabilities (Pn )

together with a beta detector

- High neutron detection efficiency

- Constant neutron detection efficiency for a wide range of neutron energies

(from thermal up to 5 MeV)

Main properties

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BELEN-48 detectorProperties of counters

Dimensions of polyethylene matrix

Overall view

Cross section of BELEN-48 detector

Beam hole

Counter holes

Polyethylene matrix

Polyethylene matrix

8 blocks, 10 cm thickness

Shielding, 20 cm thick

Total dimensions of matrix:

90 x 90 x 80 cm3

Mass aprox. 900 kg

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BELEN-48 detector

Polyethylene matrix

Supporting/Positioning structure

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BELEN-48 detectorNeutron detection efficiency up to 2 MeV

Mean efficiency = 45%

Efficiency factor = 1.07

Neutron detection efficiency up to 5 MeVMean efficiency = 43%

Efficiency factor = 1.31

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BELEN-48 detectorElectronics and Triggerless Data Acquisition System

- Each counter connected to one of the inputs of MPR16-HV preamplifier (16 channels)

- Two double output HV modules

- Differential outputs of preamplifiers connected to a STM16+ shaping amplifier (16 channels/each)

- ADC SIS3302 from STRUCK

- A triggerless DACQ system developed by the IFIC (Valencia-Spain) to do an offline analysis

- The DACQ system includes the GasificTL software developed at IFIC

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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.7/9

BELEN detector

STATUS OF THE TDR

Submitted on January-2014Submitted on January-2014

(to be approved…)

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