用推广的Viola-Seaborg公式计算α衰变寿命

根据Audi等编评的最新核数据表, 对Z≥84, N≥128的核的α衰变实验寿命用Viola-Seaborg公式进行最小方差拟合, 得到一套新参数. 用新拟合参数计算的偶偶核的衰变寿命与实验寿命很好地符合, 平均偏差1.3倍.而对奇A和奇奇核理论寿命与实验寿命相差较远. 考虑到处于基态时奇A和奇奇核与偶偶核的主要区别在于自旋和宇称, 对Viola-Seaborg公式做了推广. 在公式中引入了离心势垒(即α粒子轨道角动量)对衰变寿命的影响. 由推广公式计算的奇A和奇奇核的寿命与实验寿命平均偏差2.5倍,最大偏差5—6倍.

Calculations of α-Decay Half-Lives by the Generalized Viola-Seaborg Formula

The Viola-Seaborg formula is a well-known formula for ~ decay half-life of heavy nuclei. In this work we obtain a set of new parameters for this formula through a least-square fit to even-even nuclei between Z = 84 and Z = 110 with N greater than 126. On average, the formula can reproduce the half-lives of heavy even-even nuclei with a factor of 1.3. In order to improve the calculated results for odd-A nuclei and for odd-odd nuclei, we obtain a generalized form of the Viola-Seaborg formula by including the influence of orbital angular momentum of ~ particle on half-lives of odd-A nuclei and odd-odd nuclei. On average, half-lives of odd-A and odd-odd nuclei can be reproduced with a factor of 2.5 by the generalized Viola-Seaborg formula.