Interaction of Fast Neutrons with Lithium and Uranium

Abstract

This work is concerned with the investigation of neutron
shielding materials that are of possible use in future fusion
reactors. Measurements and calculations have been carried out
for shield of LiF, u²³⁸ , a mixture of LiF and U²³⁸ and a
two region of LiF and U²³⁸ The neutron source was a monoenergetic
points source of energy 14.1 MeV produced by D(T,n)⁴He reaction
at the centre of a cylindrical shield.

The measurements were made with a liquid organic
scintillator (NE-213), and the gamma-ray background was rejected
by pulse shape discrimination using the zero crossing technique.

Calcuations have been carried out in spherical geometry with
a multigroup diffusion model where the uncollided flux was
calculated by the removal model. The cross-section data used came
from the UKNDL-file, and the YOM-20 cross-section set.

Measured and calculated spectra show reasonable agreement, and
do not indicate any discrepancies in the cross-section data used.

Removal cross-sections at 14.1 MeV have been experimentally
determined for the four shield assemblies and show a good agreement
with those used in the calculations which were based on the
transport cross-sections.

Date of Award	1979
Original language	English