High Efficiency Semiconductors for Nuclear Material Accounting

There is a need to develop tools and technologies to improve the detection of diversion, misuse, or sabotage of nuclear materials in nuclear and pyroprocessing facilities. To address this need, the DOE Materials Protection, Accounting, and Control Technologies (MPACT) campaign set a goal of demonstrating a lab-scale of an advanced safeguards and security system for identification and localization of nuclear materials. Neutrons and gamma rays are two signatures of nuclear materials, therefore radiation detectors would be a key in developing these tools and technologies. A dual neutron/gamma-ray detection system can be used to develop radiation maps for material that is dispersed throughout nuclear and pyroprocessing facilities. The detection of neutrons directly indicate the presence of special nuclear materials (SNM), while gamma ray detection can confirm the presence of a particular isotope. RMD is proposing the use of two different semiconductor technologies - CsPbBr3 and LiInSe2 – that can provide these capabilities in a compact and robust form-factor, combined with exceptional detection performance. Key processes related to growth and fabrication of both detector types will be studied to better determine the range of operational characteristics that these materials can provide. In order to boost detection efficiencies with larger detectors, crystal growth techniques need further optimization, along with parallel efforts in material purification to boost electronic performance. Multiple iterations of materials will be produced, with subsequent characterization of physical, chemical and electronic properties. A wide range of radiation testing will occur, primarily focused on spectroscopy in gamma ray detection, and sensitivity and selectivity for the neutron detector. At Phase 1 completion, RMD will be well positioned to move into detector construction and instrumentation design in Phase 2.The most relevant benefit of furthering the development of CsPbBr3/LiInSe2 system is improving and advancing the scope of tracking and controlling the nuclear materials and their accountability in and outside of the nuclear and pyroprocessing facilities. Other group of people would be those scientists and engineers who on the behalf of the DOE and IAEA monitor and verify nuclear installations. Another opportunity would be the creation of spectroscopy systems that can be readily employed by first responders and inspectors located at the Nation’s borders and ports.