Absolute disintegration rate and 320 keV γ-ray emission probability of 51Cr

This work describes the procedures for determining absolutely the 51Cr disintegration rate by using the 4πβ−γ coincidence and anti-coincidence counting and the sum-peak methods. A 4′′×4′′−NaI(Tl) scintillation detector was used in the γ- channel of the 4πβ−γ coincidence system for γ-ray counting. In the β-channel, a 4π gas flow proportional counter was used for counting of characteristic X-rays and Auger electrons originating from the electron capture events of the 51Cr decay scheme. Gamma spectrometry measurements by high-pure planar and coaxial germanium detectors were performed in the sum-peak method and in the determination of the 320 keV γ-emission probability of 51Cr. This latter determined value agrees with the recent values found in the literature, confirming the reliability of the three methods used in this work for the disintegration rate measurements.