A gas proportional scintillator counter for thermal neutrons instrumentation

A gaseous scintillation detector consisting of a 3He+CF4 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 photons' emission as a function of the gas mixture have been carried out indicating that filling the detector with 3He+CF4 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 CF4 concentration and operating voltages. We also studied the emission of primary light, rather strong in CF4 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