Speaker
Description
The Alpha-Gamma device at the National Institute of Standards and Technology (NIST) utilizes neutron capture on a totally absorbing $^{10}$B deposit to measure the absolute flux of a monochromatic cold neutron beam to better than 0.1% precision. Gammas produced by the boron capture are counted using high purity germanium detectors, which are calibrated using a precisely characterized alpha source and the alpha-to-gamma ratio from neutron capture on a thin $^{10}$B target. This device has been successfully operated and used to calibrate the neutron flux monitor for a beam-based neutron lifetime experiment at NIST. Here we will discuss work underway to provide systemically-distinct measurements of the $^6$Li(n,t)$^4$He and $^{235}$U(n,f) cross sections with competitive precision.