Development and performance evaluation of a multi-layer boron-lined detector for the CPHS-SANS instrument

Abstract

A position-sensitive thermal neutron detector module based on multi-layer boron-lined tubes has been developed. It is designed for the CPHS (compact pulsed hadron source) SANS (small-angle neutron scattering) instrument [Loong et al. (2012). Phys. Procedia, 26, 8–18]. The detector module consists of 64 boron-lined tubes, arranged into an eight row by eight column structure. Several key aspects of the development of the detector prototype are briefly covered, including the detector module structure design, the readout electronic system and the digital filter of neutron waveforms. Preliminary characterization reveals that the detector module could achieve an average axial spatial resolution of 5.62 mm and a good position linearity. The detection efficiency measurement shows that more than 30% efficiency can be achieved for thermal neutrons on the CPHS. A virtual experiment was conducted to evaluate the performance of the multi-layer boron-lined tubes in SANS measurement; the effect of inside detector scattering of the multi-layer detector was simulated. The result shows that, by implementing proper data reduction, the impact of inside detector scattering on the Q (momentum transfer) value and Q resolution is negligible.