Cross section of the reaction ⁹Be(γ, n) near threshold

Abstract

Six kinds of radioisotopes were used to measure cross sections of the 9 Be(γ, n) reaction near its threshold. The results obtained were 0.88 ± 0.16, 1.33 ± 0.24, 1.10 ± 0.20, 0.73 ± 0.13, 0.47 ± 0.09, and 0.18 ± 0.04 mb at 1674.7, 1705.2, 1724.9, 1778.9, 1836.0, and 2167.6 keV, respectively. The cross sections measured show a sharp peak near the threshold, and its width is narrower than that observed by Jakobson with Bremsstrahlung X-rays. Comparison of the present results with theories based on the valence neutron model indicates that the agreement is only qualitative.