Quenched and non-quenched Ar-Xe Penning mixtures as detection media for a Gridded-Microstrip Gas Chamber X-ray detector

The performance of quenched and non-quenched argon-xenon Penning mixtures in a Gridded-Microstrip Gas Chamber is studied for 5.9keV X-rays. The best energy resolution obtained was 12.7% for the 90%Ar-10%Xe mixtures. Charge multiplication gains one order of magnitude higher than in pure xenon were obtained for 95%Ar-5%Xe. With the addition of the quenching agent (methane), although the gas gain at the same anode voltage decreases, a better energy resolution of 12.3% is achieved for the 85.5%Ar-5%Xe-9.5%CH4 mixture.