A 2D pixelated stilbene scintillator detector array for simultaneous radiography with fast neutrons and gammas

Journal of Instrumentation, vol. 16, pp. P02021

Abstract

For radiography applications using fast neutrons simultaneously with gammas we have developed a detector with 16 stilbene crystals in a 4×4 2D array with a 5 mm pitch and a depth of 25 mm. The crystal array is read out by Silicon photomultipliers and custom signal processing electronics. The detector prototype was tested using a custom D-D fast neutron generator at the Paul Scherrer Institute. By applying a pulse shape discrimination algorithm the detector is able to detect and distinguish fast neutrons and gammas simultaneously. Various attenuating samples placed between the source and detector with different materials and thicknesses were tested and the measured macroscopic fast neutron cross sections were compared to what was expected. Deviations were studied with the help of detailed Geant4 simulations. The detection efficiency for D-D fast neutrons was measured to be around 10%.

Authors 4

1. R. Adams

   Paul Scherrer Institute · ETH Zurich

   Affiliation as printed

   Paul Scherrer Institut, Nuclear Energy and Safety Research Department, 5232 Villigen PSI, Switzerland

   Swiss Federal Institute of Technology, Department of Mechanical and Process Engineering, Sonneggstrasse 3, 8092 Zurich, Switzerland

2. C. Günther Aachen III. Physikalisches Institut B

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, III. Physikalisches Institut B, Templergraben 55, 52055 Aachen, Germany

3. Nina Hoeflich Aachen III. Physikalisches Institut B

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, III. Physikalisches Institut B, Templergraben 55, 52055 Aachen, Germany

4. Oliver Pooth Aachen III. Physikalisches Institut B

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, III. Physikalisches Institut B, Templergraben 55, 52055 Aachen, Germany