A cluster study of the nuclei 212Po and 218Rn

[摘要] ENGLISH ABSTRACT: A binary cluster model is used to investigate the properties of the ground state band of 212Po,modelled as a 208Pb-alpha core-cluster system. The results obtained using a microscopic coreclusterpotential are compared to those obtained with a purely phenomenological potential. Thetwo potentials were found to exhibit similar surface behaviour and thus give similar predictionsfor the ground state alpha decay half-life. They however generate very different energy spectra,with the results from the phenomenological potential clearly superior. We optimize thephenomenological potential parameters, and propose an additional short range interaction toimprove the underbinding generally found for the J¼ = 0+ ground state. We then investigatetwo possible scenarios for generating the negative parity states in 212Po. We find that both arenecessary in order to produce low-lying negative parity states which are able to decay via electricdipole transitions to the positive parity states of the ground state band. Finally we present anovel calculation of the properties of the low-lying positive and negative parity states of 218Rndescribed as a doubly closed 208Pb core plus a 10Be cluster.

[发布机构] Stellenbosch University