Study on the Correction Method for the Dead-Time Effects of Neutron Detectors Due to Pulsed Radiation

Gas detectors based on a He-3 proportional counter play an important role in monitoring the ambient dose equivalent in nuclear reactors and particle accelerators, and the time resolution of such gas detectors is directly related to the accuracy of dose equivalent values when gas detectors are used in pulsed neutron fields. In this article, the dead-time of a proportional He-3 counter is measured experimentally, and two methods to correct for the omitted counts resulting from the dead-time effect are adopted. The moderation time of neutrons passing through the moderator of a neutron detector is calculated by means of Monte Carlo simulation software; thus, the equation between the neutron counting rate and the correction coefficient in accelerator radiation fields is deduced. In the other method, the parameters of the correction equation are derived experimentally in the pulsed radiation fields around accelerators, and the correction equation is determined. The dead-time effects of neutron detectors due to pulsed radiation can be corrected effectively by using the two methods introduced in this paper.