A 2D gas scintillation detector for thermal neutrons

A 2D position sensitive gas scintillation detector for thermal neutrons is under development as part of the European FP7 NMI3 JRA program (Project 226507). The aim of the project is to have a detector with: sub-millimetre position resolution, high rate capability (>1 MHz), high efficiency (>50% for 1 Angstrom neutrons) and an active area of 200×200 mm². A detector with these characteristics is of interest for retlectometry and micro-focusing SANS instruments at the neutron scattering facilities. The detector under development is a gas scintillation proportional counter (GSPC) that uses the light emitted in the gas avalanche to determine the position of neutrons absorbed inside the detector using the Anger camera principle. The device for the gas multiplication is an MSGC and the gas is a mixture of ³He and CF₄, Despite the worldwide shortage of ³He, it still represents a valid option for small detectors that require high efficiency like the one under development in this project. The status of the project will be reported in the following sections.