Large-area imaging detector for neutron scattering based on boron-rich liquid scintillator

We discuss a new thermal-neutron imaging detector that combines a neutron converter coupled to a position-sensitive gaseous photodetector. The neutron converter consists of a thin (0.5 mm) layer of boron-rich liquid scintillator. It is viewed by an atmospheric-pressure, gas-avalanche photomultiplier with a bialkali photocathode. Scintillation-induced photoelectrons are multiplied by a cascade of Gas Electron Multipliers (GEM). The multi-GEM supplies the pulse-height, time and position information for each converted neutron. Such a fast, large-area detector can operate at high radiation flux.