Relative intensities of prompt γ-rays from the 35Cl(n,γ)36Cl reaction with thermal neutrons as secondary γ-ray intensity standards.

The relative intensities of 16 prompt γ-rays from the (35)Cl(n,γ)(36)Cl reaction with a thermal neutron were precisely determined as secondary γ-ray intensity standards with HPGe detectors. The detection efficiencies were calibrated from 0.2 to 10.8 MeV using the standard sources (152)Eu and (56)Co and the (14)N(n,γ)(15)N reaction. We performed appropriate analyses for the evaluation of doublet peaks, subtraction of mixing with escape γ-rays and other corrections; consequently, the values were determined within 1% accuracy. Relative intensities in the range of 0.7 to 8.6 MeV are proposed as reliable secondary standards for 16 γ-rays.