Eur. Phys. J. A (2017) 53: 179
https://doi.org/10.1140/epja/i2017-12363-9

Regular Article - Theoretical Physics

Neutron moderation theory with thermal motion of the moderator nuclei

Department of Theoretical and Experimental Nuclear Physics, Odessa National Polytechnic University, Odessa, Ukraine

^* e-mail: siiis@te.net.ua

Received: 4 May 2017
Accepted: 4 August 2017
Published online: 13 September 2017

Abstract

In this paper we present the analytical expression for the neutron scattering law for an isotropic source of neutrons, obtained within the framework of the gas model with the temperature of the moderating medium as a parameter. The obtained scattering law is based on the solution of the general kinematic problem of elastic scattering of neutrons on nuclei in the L-system. Both the neutron and the nucleus possess arbitrary velocities in the L-system. For the new scattering law we obtain the flux densities and neutron moderation spectra as functions of temperature for the reactor fissile medium. The expressions for the moderating neutrons spectra allow reinterpreting the physical nature of the underlying processes in the thermal region.