Phenomenological formula for alpha-decay half-lives

• Published in: Journal of nuclear science and technology Vol. 49; no. 8; pp. 816 - 823
• Main Author: Koura, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis 01.08.2012; Atomic Energy Society of Japan
• Subjects: alpha-decay; Applied sciences; Energy; Energy. Thermal use of fuels; ENSDF; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Nuclear fuels; nuclear structure; superheavy nuclei; Charged particle; superheavy nuclei; Alpha decay; Modeling; ENSDF; alpha-decay; nuclear structure; Half life; Nuclear reactor
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/00223131.2012.704158

A phenomenological formula is presented for the partial half-life from the Q value for α decay. It is constructed in a conventional way by considering the penetrability of a charged particle in a spherical Coulomb potential. Parameters in the formula are fixed because they are determined by physical constants except for the following three adjustable parameters: the product of the collision frequency of an α particle and the formation probability, N; the distance between the charge radius and the radius of an inner point of the Coulomb barrier, r 0 ; and the odd-mass hindrance, h 0 . The values obtained for the three adjustable parameters are reasonable, in contrast with those of conventional models such as the Viola-Seaborg formula. The root-mean-square deviations from experimental partial half-lives for even-even, odd-A, and odd-odd nuclei are 0.344, 0.740, and 0.940 (in log 10 ), respectively. The obtained formula gives half-lives that are two or three times longer than those obtained using the Viola-Seaborg formula in the superheavy nuclear mass region.