Air Effects on Body Currents and Charging Voltage of an Irradiated Isolated Body

We have conducted an experiment to measure the effects of air on the currents and charging voltage of an isolated body exposed to X-rays. We found the currents peaked at 10 mtorr while the charging voltage monotonically decreased with pressure. The measurements indicate that the body charges to the average electron energy in a vacuum but to a considerably lower value as the pressure is increased to 1 torr. At 10 mtorr, the body current was measured to be almost 30 times that measured in vacuum and about six times higher than at 1 torr.