(n, α) Cross-section measurement using a gaseous sample and a gridded ionization chamber

We developed a method of (n, α) cross-section measurement using a gaseous sample in a gridded ionization chamber (GIC). This method enables us to measure the cross section of gaseous samples, such as C, O and N, with very large solid angle close to 4π without distortion due to energy loss in the sample. The detection efficiency, which is difficult to estimate for gaseous samples, was estimated by using GIC signals and tight neutron collimation. This method was verified through the 12C(n, α0)9Be cross-section measurement for 14.1 MeV neutrons.