Preparation of a liquid nitrogen target for measurement of γ-ray in the ~(14)N(n,γ)~(15)N reaction as an intensity standard in energy region up to 11 MeV

摘要

For determination of relative γ-ray intensities up to 11 MeV in the ~(14)N(n,γ)~(15)N reaction, we have developed a liquid nitrogen (Ni) target which contain no hydrogen (H) to improve the accuracy of γ-ray intensities. The ratio of the relative uncertainties for the liquid nitrogen to that for the melamine (C_3H_6N_6) widely used was improved by a factor of 2 above 2.2 MeV and a factor of 3 - 6 below 2.2 MeV. It has been shown that the liquid nitrogen target is useful for reduction of the 2.2 MeV ?γ-ray from the ~1H(n,γ)~2H reaction and improvement of statistics.