Design, fabrication and characterization of neutron irradiation facility using accelerator-based photoneutron source

摘要

In this paper we describe the design of a neutron generator assembly using an electron accelerator. We have carried out design calculations for this assembly by optimizing neutron source strength and maximizing output neutron flux at a reasonable L/D ratio keeping in view the radiography applications. For this purpose, detailed Monte Carlo calculation using EGS-4 code was carried out to estimate photon flux. The results of EGS4 calculations are used in source definition card of MCNP simulation to compute neutron source strength from Beryllium in order to arrive at an optimum design. The parameters such as neutron source strength; collimation ratio etc. were optimized. The thermal neutron flux at each position of this assembly including those at the end of collimator, Cd ratio, neutron-to-gamma ratio has been estimated. Experimental measurements of these parameters are in good agreement with simulation results.