Wavelength-based neutron/gamma ray discrimination in CLYC
We investigated the optical components of Cs2LiYCl6:Ce (CLYC) as a possible path to particle discrimination by measuring the effects of optical filters on the shape of the waveform and comparing filtered waveforms to unfiltered ones. Crystals packaged with two optical windows were viewed by two photomultiplier tubes operated in coincidence to be certain that the signals from the same event were analyzed. We applied long-pass optical filters with cut-off wavelengths from 280 to 455 nm, and bandpass filters with cut-off wavelengths at 313, 350, 385, and 425 nm. Waveforms from gamma rays were significantly sharpened by the 313 nm bandpass filter because this filter cut out self-trapped exciton luminescence, while neutron waveforms were largely unaffected by filtering. Cumulative distribution functions generated from average filtered waveforms indicate that the neutron/gamma assignment can be made 44 ns by applying a Kolmogorov-Smirnov test comparing an acquired waveform to the average filtered waveforms.
Passive Gamma-Ray and Neutron Imaging Systems for National Security and Nuclear Non-Proliferation in Controlled and Uncontrolled Detection Areas: Review of Past and Current Status
Global concern for the illicit transportation and trafficking of nuclear materials and other radioactive sources is on the rise, with efficient and rapid security and non-proliferation technologies in more demand than ever. Many factors contribute to this issue, including the increasing number of terrorist cells, gaps in security networks, politically unstable states across the globe and the black-market trading of radioactive sources to unknown parties. The use of passive gamma-ray and neutron detection and imaging technologies in security-sensitive areas and ports has had more impact than most other techniques in detecting and deterring illicit transportation and trafficking of illegal radioactive materials. This work reviews and critically evaluates these techniques as currently utilised within national security and non-proliferation applications and proposes likely avenues of development.
DECAY SPECTROSCOPY (DESPEC) AT THE NEW FAIR-NUSTAR FACILITY
This contribution describes DESPEC (DEcay SPECtroscopy) which together with HISPEC (see the corresponding contribution to this conference) constitutes one of the proposed and accepted joint experiments of NuSTAR (Nuclear STucture, Astrophysics and Reactions), the part of the new FAIR facility that focuses on the production and study of beams of radioactive nuclei created by the fragmentation method.