Beta-Delayed Proton Emission: A New Series of Precursors and the Measurement of 10 exp -16 S Nuclear Lifetimes

摘要

We have now obtained results on a new series of even-Z precursors with Tsub(z) = +1/2. Like all known heavy precursors, the nuclei so far identified - exp 65 Ge, exp 69 Se, exp 73 Kr, exp 77 Sr, exp 81 Zr and provisionally exp 85 Mo - exhibit broad proton continua. However, the availability of such a series of nuclei makes it possible to extract a systematic picture of the beta-decay strength function as well as level densities, widths and decay energies from the observed spectra. By the addition of a new experimental technique we have also been able to determine the absolute values of the widths through direct measurement of the average lifetime of states populated in the emitter. These data all provide stringent tests of model calculations and mass formulae in a region of nuclei with N approximately Z, far removed from the valley of stability. (Atomindex citation 09:375180)