摘要
Half-lives ofαdecay for Z≥84 nuclei are calculated based on the WKB theory applied for a phenomenological potential barrier composed of a centrifugal contribution and a screened electrostatic interaction represented by a Hulthen potential.For favored decays,the model has a single adjustable parameter associated with the screening of the electrostatic potential.The description of half lives for unfavored decays requires an additional hindrance term.A good agreement with experimental data is obtained in all considered cases.The evolution of the screening parameter for each nucleus revealed its dependence on shell filling.The model is also used for theoretical predictions on a few nuclei with uncertain or incomplete decay information.