Superconducting Gamma/Neutron Spectrometer Task 1 Completion Report Evaluation of Candidate Neutron-Sensitive Materials
A review of the scientific literature regarding boron- and lithium-containing compounds was completed. Information such as Debye temperature, heat capacity, superconductivity properties, physical and chemical characteristics, commercial availability, and recipes for synthesis was accumulated and evaluated to develop a list of neutron-sensitive materials likely to perform properly in the spectrometer. The best candidate borides appear to be MgB{sub 2} (a superconductor with T{sub c} = 39 K), B{sub 6}Si, B{sub 4}C, and elemental boron; all are commercially available. Among the lithium compounds are LiH, LiAl, Li{sub 12}Si{sub 7}, and Li{sub 7}Sn{sub 2}. These materials have or are expected to have high Debye temperatures and sufficiently low heat capacities at 100 mK to produce a useful signal. The responses of {sup 10}B and {sup 6}Li to a fission neutron spectrum were also estimated. These demonstrated that the contribution of scattering events is no more than 3% in a boron-based system and 1.5% in a lithium-based system. This project is concerned with the development of materials for use in a cryogenic neutron spectrometer and is complementary to work in progress by Labov at LLNL to develop a cryogenic gamma ray spectrometer. Refrigeration to 100 mK lowers the heat capacity of these materials to the point that the energy of absorbed gamma and x rays, nuclei scattered by fast neutrons, and ions from (n, {alpha}) reactions produce a measurable heat pulse, from which the energy of the incident radiation may be deduced. The objective of this project is the discovery, fabrication, and testing of candidate materials with which a cryogenic neutron spectrometer may be realized.
- Research Organization:
- Oak Ridge Y-12 Plant (Y-12), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP) (US)
- DOE Contract Number:
- AC05-00OR-22800
- OSTI ID:
- 804539
- Report Number(s):
- Y/DX-2490 R1; TRN: US0300690
- Resource Relation:
- Other Information: PBD: 20 Jun 2002
- Country of Publication:
- United States
- Language:
- English
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