Investigation of Neutron-Physical Characteristics of the Irradiation Capsule Designed for Radiation Coloring of Topaz in the WWR-K Reactor

Abstract

This paper presents the results of the study of neutron-physical characteristics of an irradiation capsule designed for radiation coloring of topazes. The studies were performed in the core of the critical facility. Sandwich screen made of boron carbide powder and tantalum foil was used to cut off thermal neutrons inside the capsule. It is shown that using sandwich screen the thermal neutron flux is reduced by 8 times, and the fast neutron flux density is practically unchanged. The activation of the tantalum monitor is reduced by more than a factor of 2. The reactivity effect from loading the irradiation capsule with the screen into the core is minus 0.9% Δk/k.