Abstract The decay data for 186 even-even alpha emitters have been analyzed, and used as input in the ALPHAD code to extract nuclear radius parameters (r0) for the daughter nuclides. The ALPHAD code employs Preston's spin-independent formalism to calculate alpha decay probabilities. A suite of databases available at the website of the National Nuclear Data Center (NNDC), Brookhaven National Laboratory was consulted to ensure the completeness and reliability of available experimental data pertaining to alpha decays of all the even-even nuclides in the entire nuclear landscape. The literature available up to June 2020 has been consulted. In addition to updating Q α values, half-lives, and other relevant quantities for all the even-even alpha emitters, 26 new even-even alpha emitters, and 164 references published since 1997, mostly in primary nuclear physics journals, have been added to the previous evaluation by Y.A. Akovali [1] in 1998, with a literature cutoff date of January 1997. We also present systematics of r0 parameters for even-even nuclides, and find that the radius parameters in an isotopic chain exhibit a regular pattern as a function of parent neutron number, showing a minimum at major closed shells, e.g. at N=126, increasing sharply above the closed shells, followed by a smoothly decreasing trend towards the next shell closure. The r0 parameters for even-even nuclides can be used as input parameters to calculate hindrance factors for the alpha decay of odd-A and odd-odd nuclides. We have also modified the original ALPHAD code so that the r0 parameters for the odd-A and the odd-odd nuclei can be automatically calculated using the present data file for r0 parameters of even-even daughter nuclides.

中文翻译：

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来自 alpha 衰变的偶数核的核半径参数 (r0)

摘要 分析了 186 个偶偶 α 发射器的衰变数据，并将其用作 ALPHAD 代码的输入，以提取子核素的核半径参数 (r0)。ALPHAD 代码使用 Preston 的自旋无关形式来计算 alpha 衰减概率。布鲁克海文国家实验室的国家核数据中心 (NNDC) 网站上提供了一套数据库，以确保与整个核领域中所有偶偶核素的 α 衰变有关的可用实验数据的完整性和可靠性。查阅了截至 2020 年 6 月的可用文献。除了更新所有偶偶 alpha 发射器的 Q α 值、半衰期和其他相关数量、26 个新的偶偶 alpha 发射器和自 1997 年以来出版的 164 篇参考文献外，主要在初级核物理期刊中，已被添加到 1998 年 YA Akovali [1] 的先前评估中，文献截止日期为 1997 年 1 月。我们还介绍了偶偶核素的 r0 参数的系统学，并发现半径同位素链中的参数显示出作为母体中子数函数的规则模式，在主要闭合壳处显示最小值，例如在 N=126 处，在闭合壳上方急剧增加，然后朝着下一个壳闭合平滑下降。偶偶核素的 r0 参数可用作输入参数来计算奇数 A 和奇数核素的 α 衰变的阻碍因子。