Author/Authors :
S. Bayer، نويسنده , , A.P. Byrne، نويسنده , , G.D. Dracoulis، نويسنده , , A.M. Baxter، نويسنده , , T. KIBEDI، نويسنده , , F.G. Kondev، نويسنده ,
Abstract :
Excited states in the nuclei 210At and 211At have been studied using 208Pb(7Li,xn) reactions. Detailed spectroscopy of levels up to 30ℏ has been achieved. New isomeric levels arising from core-excited states were observed, with the highest-lying isomers attributed to a coupling of the π[h9/22i13/2] configuration to double neutron-particle–hole excitations. Clear relationships between the states observed in 210At and 211At were identified. Semiempirical shell-model calculations reproduce very well the yrast states in both nuclei. Uncertainty in the modeling of core-polarization was seen as a limiting factor in the calculation of accurate level energies for core-excited states.
Keywords :
211At , 210At , 208Pb (7Li , Calculated levels , E=32–44 , B(?) , 53–56 MeV , Semiempirical shell-model calculations , Measured ??(t) , yrast configurations , X?(t) , Core-excitation , E? , residual interactions , J? , octupole coupling , ?m , core-polarization , reduced transition probabilities , 210At and 211At deduced levels , enhanced transitions , Enriched targets , Compton suppressed Ge detectors , pulsed-beam , xn) , configurations
