ELECTRONIC DETECTOR FOR NEUTRON DOSIMETRY

We studied the possibility of realizing personnel neutron dosimetry using an individual microprocessor controlled device, working in real time (ratemeter). The energy range we are interested in goes from the energy of thermal neutrons up to about 5 MeV. The device, based on a differential method, is partially free from interfering signals (interactions of gamma rays and neutrons on silicon) as well as the sources of background. Besides, a boron implanted (CH2)n "converter" performs the neutrons to secondary charged particles conversion. The converter, which has been optimized using a Monte Carlo method, shows a dose equivalent response almost independent of neutron energy. The secondary charged particles are detected by diodes. The design of the system led us to study the symetry of the two diodes. We showed that a dose equivalent level as low as 30-mu-Sv can be obtained for thermal and fast neutrons, and that a dose equivalent rate of a hundred-mu-Sv/h can be measured.