NUCLEAR EMULSION ACTIVATION AND FAST NEUTRON DOSIMETRY

ABSTRACT A new method for fast neutron dosimetry has been developped. This method is based on the property of the nuclear emulsion to leave after processing, silver grains along the trajectory of charged particles namely along those of recoil protons produced by the elastic scattering of incident neutrons with the hydrogen atoms of the emulsion. The number of such grains can be measured by activation of the emulsions with low energetic neutrons and by counting the γ-rays they emit. This γ-ray counting gives after calibrations a measurement of the flux of incoming neutrons and so far of the dose deposited inside the material. We give here the results of measured response of different kinds of emulsions exposed at known gamma and neutron fluxes. A simultaneous Monte Carlo analysis is done in order to simulate the experimental conditions for a fast neutron dosimeter which can be used around nuclear reactors. Results obtained for a known neutron source are also given.