New Simple Measuring Method of Intensity of Pulsed Nuclear Radiation by Counting Delayed-Pulses Produced in GM Counter

Abstract

The present work is an attempt to develop a simple dosimeter for measuring the pulsed radiation by the counting of the delayed-pulses. According to our recent study, the delayed-pulses are a kind of Geiger-Müller type discharges which occur being delayed after the time of an irradiation due to negative ions produced in the organic quenched GM counter by incident radiations. It was also made clear that the counting characteristics of the main-pulse being produced immediately after the irradiation exhibits the saturating mode against the intensity of the pulsed radiation, on the contrary, the number of counting of the delayed-pulses increases with the intensity of the pulsed radiation, even when its intensity is extremely increased We have succeeded in determining the conditions that improve both the counting number of the delayed-pulses and its linearity against the intensity of pulsed radiation. The measurement of pulsed radiation intensity could simply be made by the counting method of delayed-pulses, even when the pulse width of pulsed radiation is smaller than the dead time of the GM counter. Especially, the intensity measurement for one shot pulsed radiation was made possible by this method In practice, this simple measuring method made possible to measure fairly well the intensity of the pulsed radiation of the order 10⁻⁴ to 1μR for one burst irradiation by the counting of the delayed-pulses.