Measurement of the activity and determination of the half-life of 225Ac at POLATOM

A method for absolute measurements of the 225Ac activity in equilibrium with its progeny was developed. Measurements were performed using the triple-to-double coincidence ratio (TDCR) method in two different TDCR counters. The activity concentration of an 225Ac solution was determined and the solution was sent to the SIR system for a comparison. The half-life of 225Ac was determined by one of the TDCR counters and found to be 9.9150(63) days.

Automated summary

A method for absolute measurements of 225Ac activity in equilibrium with its progeny was developed using the triple-to-double coincidence ratio (TDCR) method in two different TDCR counters. The activity concentration of 225Ac solution was determined and compared with the SIR system. The half-life of 225Ac was determined to be 9.9150(63) days using one of the TDCR counters.