A gas proportional scintillator counter for thermal neutrons instrumentation

A gaseous scintillation detector consisting of a 3 He+CF 4 filled MSGC detector coupled with an optical readout has been investigated for an application for high-resolution and high counting rate position-sensitive neutron detector. Measurements of the photonsʹ emission as a function of the gas mixture have been carried out indicating that filling the detector with 3 He+CF 4 is a very good choice also from the point of view of optical readout and not only for charge readout. The light yield has been systematically measured as a function of the CF 4 concentration and operating voltages. We also studied the emission of primary light, rather strong in CF 4 mixtures, which allows the observation of the light signal even in the absence of high voltage on the electrodes. Finally, some measurements of the position resolution will be presented.