Performance of a cooled sapphire and beryllium assembly for filtering of thermal neutrons

Abstract

Transmission measurements have been made at 80 and 300 K for sapphire and beryllium filters in service on a triple-axis neutron spectrometer. The measurements agree with earlier work and confirm that sapphire is a more effective neutron filter than either quartz or silicon. Curves of transmission as a function of neutron wavelength are presented in a form useful for planning thermal neutron experiments in which higher-order thermal neutrons and fast neutrons must be removed from the incident beam.