A novel angle-independent neutron detector based on CR-39.

Abstract

CR-39 offers numerous advantages for neutron detection, yet its strong angular dependence has long compromised the accuracy of measurements. To address this issue, this work proposes a novel cubic neutron detector consisting of six CR-39 elements. By taking the average response of the six elements as the measurement metric, the angular dependence is effectively suppressed. To accommodate the broad energy range of realistic neutron fields, a compact dual-converter structure is designed, in which polyethylene and boron nitride converters are coupled to the two faces of CR-39 element for fast- and thermal-neutron detection, respectively. Simulation results show that the angular variation in detector response remains below 12% for both fast- and thermal-neutron detection over the full solid angle, whereas a conventional single CR-39 element exhibits a response variation exceeding 300%. This superior angular independence has also been verified experimentally.