A versatile neutron beam filter facility with silicon and iron filters

A versatile neutron beam filter facility has been installed at the University of Missouri Research Reactor Facility (MURR). With this facility, the filter tubes can be changed easily and safely during a reactor shutdown while the components within a filter tube can be inserted or removed with the reactor operating at low power. To date two filters have been made for this facility. The Si filter provides a 144 keV neutron flux of about 106 n/cm2s, and the Fe filter a 24 keV neutron flux of about 107n/cm2s. Spectrum measurements through 210cm of single crystal Si have shown that an increase in the thickness of Si significantly reduces the intensity of both the gamma and low energy neutron background. (Auth.)