Design of a Novel Capture-Gated Neutron Spectrometer With a CLYC Scintillator

A novel capture-gate neutron spectrometer with a CLYC (Cs<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>LiYCl<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub>:Ce) scintillator and a liquid scintillator has been developed for measuring fast neutrons and studying cosmic neutron spectrum detection. The detector consists of a liquid scintillator surrounding a central CLYC scintillator, designed for neutron capture after moderation. The CLYC scintillator can be easily replaced, allowing flexibility in its application. Two CLYC scintillators are compared: one enriched with 6Li, which has a relatively high thermal neutron cross-section, and one enriched with <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup>Li, which has significantly reduced thermal neutron capture. The spectrometer was tested in a monoenergetic neutron field from 3.2 to 14.8 MeV. Pulse shape discrimination was employed to separate neutron and gamma-ray events, and neutron identification relied on coincidence signals from both scintillators. The <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup>Li-enriched CLYC scintillator demonstrated high neutron event efficiency below 3.2 MeV, while the <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup>Li-enriched CLYC scintillator showed higher efficiency at 14.8 MeV. This approach enhances the efficiency of fast neutron spectroscopy for cosmic neutron spectrum measurements.