It should be noted however that the small mass and high energy of electrons make them drift 100,000 times faster than ions. Thus, the current is mainly due to the drifting electrons with only a small fraction due to the drift of ions Despite the multiplication due to secondary ion pairs, the ampere-meters register currents proportional to the numbers of primary electrons caused by radiation entering the detectors. Thus, currents of proportional chambers correspond to amounts of ionization radiation entering the proportional chamberIt should be noted, however, that the small mass and high energy of electrons make them drift 100,000 times faster than ions. Thus, the current is mainly due to the drifting electrons with only a small fraction due to the drift of ions. Despite the multiplication due to secondary ion pairs, the ampere-meters register currents proportional to the numbers of primary electrons caused by radiation entering the detectors. Thus, currents of proportional chambers correspond to amounts of ionization radiation entering the proportional chamber