Abstract
The half-life of the ground state was determined by means of -ray spectroscopy, following for 728 days the growth of its -decaying daughter nuclide . Using a chemically purified source containing and nuclides, -ray singles measurements were carried out using a 25% coaxial Ge detector. The areas of the strongest 333.37- and 388.17-keV -ray peaks, produced in the decay of , and the 661.66-keV peak, produced in the decay of , were determined. The measured activity of the latter was used to account for geometrical and dead-time corrections to the efficiency of the spectrometer, thus minimizing the systematic uncertainties associated with long-time, -ray counting measurements. Using the growth with time of the ratio of the 388.17- and 661.66-keV -ray peaks, a value of d (the uncertainty quoted is one standard deviation, ) for the half-life of the ground state was determined. The -decay end-point energy of was measured with a passivated implanted planar silicon detector to be keV.
- Received 19 August 2014
DOI:https://doi.org/10.1103/PhysRevC.90.044302
©2014 American Physical Society