Patent ID: 6621884
Filing Date: 2003-09-16
Classification: G01T

Abstract:
A method for monitoring the neutron sensitivity of a neutron detector, in which at least one of an anode and a cathode arranged to face each other is coated with a nuclear fission substance containing a parent nuclear species and an ionizing gas is loaded in the space between the anode and the cathode, comprising the steps of:applying voltage of a predetermined potential difference between the anode and the cathode under the state that the nuclear detector is not irradiated with neutrons so as to measure an &agr;-ray current (I&agr;) flowing between the anode and the cathode by the ionization gas caused by the &agr;-ray emitted from a nuclear fission substance; obtaining, with the monitoring region in which the applied voltage and the &agr;-ray current (I&agr;) bear a substantially linear relationship over a range of at least 50V of the applied voltage, an extrapolated zero-volt &agr;-ray current (I&agr;0) at 0V of the applied voltage between the anode and the cathode from said proportional relationship by an extrapolating method; and determining said neutron sensitivity based on a correlation between the extrapolated zero-volt &agr;-ray current (I&agr;0) and a predetermined relationship of neutron sensitivity to zero-volt &agr;-ray current.