The influence of cylindrical absorbing channels on a tilted neutron flux distribution

Abstract

Formulae are presented for determining the response coefficient (the 'dipole' coefficient) of the asymptotic neutron flux distribution in the medium surrounding a neutron absorbing rod when, in the absence of the rod, the flux in the medium is of linear form. The formulae are based on a variational approximation for the coefficient. The medium surrounding the rod is assumed to be isotropically neutron scattering and non-absorbing. The rod may be composite in form; a homogeneous, purely neutron-absorbing inner region surrounded by a uniform, weakly neutron-absorbing sheath or an air-gap or both. The one-velocity approximation is made. The rod is of infinite height and the neutron sources are at infinity.