Activity standardization and half-life measurement of 177Lu

The activity of the 177Lu solution has been measured by means of the CIEMAT/NIST efficiency tracing method. This result has been compared to the previous obtained results received from 4 pi beta(LS)-gamma coincidence and anti-coincidence counting. The activities determined with various methods have been found to be consistent. The decay curve of the 177Lu solution has been followed in the TDCR counter to determine the half-life of this isotope. The half-life has been separately determined for double and triple coincidence events. The arithmetic mean value of these two results has been found to be T1/2 = 6.6489(52) d.