Measurement of the absolute gas gain and gain variations study in straw-tube detectors

Abstract

We present the results of the absolute gas gain measurement of a straw drift-tube filled with a binary gaseous mixture Ar-CO2(90-10) at 2 bar absolute pressure. The measurement has been performed using an intense 1.3 GBq 137Cs-source producing the primary ionization current. The results, as a function of the high voltage and gas parameters, were fitted and parameterized with a Diethorn's formula