Standardization and decay data of 237Np

This paper reports contributions from participants in the EUROMET project (No. 416) which was entitled “ 237Np research into problems relating to purification, characterization and standardization”. Primary standardizations were made by the defined low solid angle, coincidence, 4 πα, 2 πα and liquid scintillation counting methods. Secondary standardizations were made with calibrated gamma-ray spectrometers. Absolute X-ray, gamma-ray and alpha-particle emission probabilities were also determined. The results for the successful conclusion of both primary and secondary standardization are presented together with the values for alpha-particle and gamma-ray emission probabilities determined in this exercise. Several significant inconsistencies remain with the gamma-ray emission probabilities, and these are highlighted.