Self-induced space charge effect on gas gain in proportional counters

Abstract

In the measurement of radiation using a proportional counter, energy linearity is lost at high gas gain, which is called the self-induced space charge effect. The dependence of the effect on the diameter of anode wire and the pressure of counting gas was investigated using methane gas flow proportional counters for X-rays with energies of 0.64, 1.5 and 5.9 keV. A theoretical explanation of the effect is also given. The effect increases with both increasing X-ray energy and pressure of the counting gas and with descreasing anode wire diameter.