Temperature dependence of the nSpec fieldable neutron spectrometer

• 全文链接
• 请求原文

作   者：

Borgwardt, T. C.;  Oukrop, L.;  Bartlett, K. D.;  Smith, K.;  Williamson, E.;  Meierbachtol, K. C.;  Febbraro, M.; 

作者机构：

Air Force Inst Technol;  Los Alamos Natl Lab; 

关键词：

Spectrum unfolding;  EJ276D;  Temperature dependence;  Fieldable;  Fast neutron spectroscopy;  Organic scintillator; 

期刊名称：

Nuclear Instruments and Methods in Physics Research,Section A.Accelerators, Spectrometers, Detectors and Associated Equipment

i s s n：

0168-9002

年卷期：

2025 年 1072 卷

页   码：

摘   要：

Fieldable instruments can encounter a variety of environments during their use. A recent fieldable fast neutron spectrometer, nSpec, has been exploring alternate materials for further ruggedizing the system. One of these materials, EJ276D, is a plastic scintillator which provides several benefits over the current liquid scintillators used in nSpec, including an operating temperature range that is more closely matched to the limits of the electronics in the system. In the following work, the temperature dependence of EJ276D is studied from-10 to 50 degrees C. The temperature dependence of the calibration and resolution of the detector were characterized using basic gamma-ray sources, while the characterization of the light output quenching for neutron interactions was done utilizing the Los Alamos Neutron Science Center (LANSCE). The results show the calibration varies in a manner and amplitude consistent with the temperature dependence of the PMT, while the resolution changes little for pulse integrals, but does show a larger change for pulse heights. The pulse shape discrimination shows an increase with temperature. These factors taken together indicate increased singlet quenching and triplet annihilation reactions as temperature increases; however these two reactions compensate for each other, resulting in a negligible change in the total light output. The quenching due to neutrons was characterized using pulse integrals and shows consistent results at each temperature. The measured responses to neutrons at different temperatures was also used to perform spectrum unfolding on a252Cf source measured at room temperature. These unfolded spectra show consistent results with no observed systematic trends with temperature.