Energy behaviour of neutrons generated by Witch-type distributed axi-symmetrical deuteron beams accelerated onto plane tritium targets

This paper is an analytical study of the spatial dependency of the d-T neut ron energy in the vicinity of a homogeneous tritium-occluded plane target. Close to the target, and along the path of incidence of axially symmetric d euteron beams, the transverse density of accelerated deuterons is assumed t o be governed by a law approximated by the 'Witch' function. In particular circumstances, the elementary neutron emission process in nondispersive med ia can be considered to be omni-directional (due consideration being paid t o collision kinetics, depending upon mass and kinetic energy of particles i nvolved in the nuclear collision, nuclear reaction energy, etc.). Consequen tly, analytical expressions can be considerably simplified. By applying the classical kinetic energy and momentum conservation laws to nuclear process es, a theoretical description is obtained, taking into account the exoergic character of d-T fusion reaction. A number of expressions for energetic pr ediction of the fast neutron field are proposed. The associated relations, involving elementary functions, can be investigated using a desk-top comput er. Computationally tractable tools are of importance in the study of diver se situations such as induced reactions and activation analysis using 14 Me V neutron generators, investigations in health-physics, radiation dose meas urements, nuclear medicine, damage effects, and simulation studies. (C) 200 0 Elsevier Science Ltd. All rights reserved.