LXXXVI. Investigation of soft radiation by proportional counters—<i>V</i>. Use as a detector of ultra-violet quanta and analysis of the gas multiplication process

Summary Quantitative detection of single slow electrons liberated by light at the cathode of a proportional counter has been observed and good plateaux obtained. The distribution in amplitude of the output pulses has been measured and the shape of this distribution has been shown to correspond rather closely with the curve x 1/2 exp (-x). The variation introduced by the gas gain alone has been calculated for various fixed amounts of ionization and compared with the experimental observations on homogeneous radiations. By this means the fluctuations in the number of ion pairs released in the gas by electrons totally absorbed in the counter has been deduced. It appears that the total variation can thus be split into its two main components. These are found to be of about equal magnitude and less than predicted by current theory.