ABSOLUTE ACTIVITY MEASUREMENTS OF MOLYBDENUM 99 AND 4 7T-V ION CHAMBER MEASUREMENT OF TECHNETIUM 99m AND OF MOLYBDENUM 99 WITH INGROWN TECHNETIUM 99m

摘要

The activity of molybdenum 99 freshly separated from technetium is absolutely measured to ± 1.8 per cent, by 4πβ-γ coincidence counting. Internal conversion effects are allowed for and the completeness of the separation is checked from the growth rate of technetium 99m activity as measured in a 4Π gamma ionisation chamber. The chamber has been calibrated for molybdenum 99 with ingrown tech¬netium 99m and for pure technetium 99m and serves for routine activity measurements of solutions of these nuclides to an accuracy of ± 3 per cent.