A Measurement of the ¹⁰B(n,αγ)⁷Li Cross Section in the keV Energy Region

The ¹⁰B(n,αγ)⁷Li relative cross section has been measured using the 200-m flight path of the National Bureau of Standards Linac neutron time-of-flight facility. Results are presented from 5 to 700 keV, showing the 5/2^- level of ¹¹B at 500 keV. The neutron flux was monitored with a hydrogen proportional counter. The known n-p scattering cross section was then used to normalize the data to obtain a relative cross section. No attempt was made to obtain an absolute normalization experimentally. Overall accuracy is estimated to be better than 3% from 10 to 400 keV.