Advances in the Standard Proportional Counter Method of Fast Neutron Dosimetry

The proportional counter method for measuring fast neutron dose in the presence of gamma radiation has been considerably improved through (1) redesign of the proportional counter, (2) a study of the behavior of the counter for various filling gases, and (3) development of a more convenient form of the electronics necessary for pulse integration and dose indication. The instrument is suitable for radiobiological research, neutron physics, and shielding research, as well as radiation protection. It will be shown that the response of the instrument is within ±5% of tissue absorbed dose over the energy range of 0.5 Mev to 14 Mev.