Monte-Carlo simulations of a neutron source based on a linear electron accelerator

Neutron beams are employed in a multitude of applications, including neutron activation analysis, neutron radiography and tomography, nuclear waste assays, reactor start-up sources, studies of material response, geological analysis, calibration standards and cancer therapy. The global demand for access to neutron beams is increasing, necessitating the development of relatively simple, efficient and easy-to-use neutron sources to address the more complex challenges of scientific research and industrial application. One relatively readily available method is to use a linear electron accelerator to produce beams of fast neutrons. The neutron generator, comprising of an electron linear accelerator and a tungsten X-ray converter, is capable of producing a maximum neutron flux of 1.53<middle dot>1010 n/s to 1.45<middle dot>1013 n/s at electron energies of 10-50 MeV, with an average electron beam current of 120 mu A, corresponding to an intensity of 7.5<middle dot>1014 e/s. The results of the neutron generator modelling conducted with the FLUKA Monte-Carlo code are presented in this article for an equivalent incident beam power of 1.2-6.0 kW. The optimal tungsten converter thickness is proposed as a means of achieving the maximum neutron flux in all directions.