Gain Reduction Due to Space Charge at High Counting Rates in Multiwire Proportional Chambers

Measurements with a small MWPC of gas gain reduction, due to ion space charge at high counting rates, have been compared with theoretical predictions. The quantity ln(q/qo)/(q/qo), where (q/qo) is the relative reduced avalanche charge, has been found to be closely proportional to count rate, as predicted. The constant of proportionality is in good agreement with calculations made with a modified version of the original, simplified theory.