A position-sensitive tubular scintillator-based detector as an alternative to a 3 He-gas-based detector for neutron-scattering instruments

A position-sensitive tubular scintillator-based neutron detector is proposed as an alternative to a 3He-gas-based detector. The detector has a neutron-detecting element constructed from rolled ZnS/6LiF scintillator screens that sandwich wavelength-shifting (WLS) fibre coils (SFC element). Multiple SFC elements are enclosed in an aluminium tube in a row to form a one-dimensional position-sensitive neutron detector. The design of the WLS fibre coil, which was determined by performing basic experiments, comprised two 0.75-mm-diameter WLS fibres wound in parallel at a pitch of 1.5mm. A 64-element detector with a pixel size of 22mm×20mm (width×length) successfully demonstrated the detection principle. The tubular shape of the new detector is similar to the usual 25-mm-diameter 3He tube, making this an alternative detector with the potential to be installed in a vacuum tank for inelastic-neutron-scattering instruments.