The relationship between energies and spontaneous fission periods

This present study is an attempt to establish the relationship between energies and spontaneous fission periods of even—even nuclei. Spontaneous fission is a tunnel effect, and thus from general considerations one might expect that spontaneous fission periods, in analogy toα-decay [1, 2], would show a tendency to increase with increase in nuclear charge Z and with decrease in spontaneous fission energy E～f,? and would also depend on mass number A. In fact, for other conditions equal increase in Z leads to an increase in barrier expansion, while increase in E～f leads to a decrease in its permeability. Growth in A on the one hand increases the corrected fragment mass, thus hindering its passage through the barrier, while on the other hand it leads to increase in fragment dimensions, which reduces barrier height. By considering the influence of shell and subshell effects on E～f we may, to a certain degree, consider the influence of these effects on spontaneous fission period. For calculation of E～f the combined method was employed. Accurate experimental values of nuclear mass and transition energy [3] were used; in their absence formulas for nuclear transition energy base on the detailed experimental data of [4] were employed.