SIMPLE RELATION FOR ALPHA-DECAY HALF-LIVES

The experimental values of log10T1/2(sec) plotted vs Z(d)0.6/square-root Q(alpha) are shown to fall on a nearly universal straight line with log10T1/2(sec)=(9.54Z(d)0.6/square-root Q(alpha))-51.37, where Z(d) is the charge number of the daughter nucleus and Q(alpha) is expressed in units of MeV. This behavior also numerically comes out of the semiclassical WKB calculation of the barrier penetration factor. The fine structure in the ratio of experiment over theory is briefly discussed.