Abstract
We report on the simulation and optimization of a neutron detector based on a glass-polymer composite that achieves high gamma rejection. Lithium glass is embedded in polyvinyltoluene in three geometric forms: disks, rods, and spheres. Optimal shape, geometric configuration, and size of the lithium glass fragments are determined using Geant4 simulations. All geometrical configurations maintain an approximate 7% glass to polymer mass ratio. Results indicate a 125-mm diameter as the optimal detector size for initial prototype design achieving a 10% efficiency for the thermalization of incident fission neutrons from 252Cf. The geometrical features of a composite detector are shown to have little effect on the intrinsic neutron efficiency, but a significant effect on the gamma rejection is observed. The sphere geometry showed the best overall performance with an intrinsic neutron efficiency of approximately 6% with a gamma rejection better than 10-7 for 280-μm diameter spheres. These promising results provide a motivation for prototype composite detector development based on the simulated designs.
| Original language | English |
|---|---|
| Pages (from-to) | 168-171 |
| Number of pages | 4 |
| Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
| Volume | 784 |
| DOIs | |
| State | Published - Jun 1 2015 |
| Externally published | Yes |
Funding
This research was funded by the National Science Foundation and the Domestic Nuclear Detection Office of the Department of Homeland Security through the Academic Research Initiative Award ECCS-1348328 . The authors are grateful to Zoubeida Ounaies, Amira Meddeb, Kareem Kazkaz, and Grayson Rich for their comments and suggestions.
Keywords
- Capture-gated neutron spectrometry
- Composite detector
- Neutron detection