A SPHERICAL NEUTRON COUNTER WITH AN EXTENDED ENERGY RESPONSE FOR DOSIMETRY

A neutron counter which is applicable to spectrometry and dosimetry ov er a wide energy range has been developed. It gives energy spectra, in tegral fluences and dose equivalent of incident neutrons with energies from thermal to 15 MeV. The counter consists of a spherical polyethyl ene moderator and three slender He-3 position-sensitive proportional c ounters inserted into the moderator. The position-sensitive proportion al counters give detection position profiles of neutrons, slowed down to thermal energies in the spherical moderator, which give the above m entioned information. The responses of the counter as a function of th e neutron energy were calculated with Monte Carlo simulations. The fea sibility of the counter for applications to neutron spectrometry and d osimetry was examined with an unfolding method. It is shown that the c ounter is applicable to the spectrometry and dosimetry of neutrons ove r a wide energy range.