ISSN:
1434-601X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Usingα-particles of energies 35–51 MeV and in-beam conversion electron andγ-spectroscopy techniques, a 4.0±1.7 μs core-excited 19+ isomeric state in210At with ag-factor of 0.737±0.025 has been observed at an excitation energy of 4027.7 keV. The 19+ state is suggested to have the $$\pi h_{{9 \mathord{\left/ {\vphantom {9 2}} \right. \kern-\nulldelimiterspace} 2}}^2 i_{1{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} vg_{{9 \mathord{\left/ {\vphantom {9 2}} \right. \kern-\nulldelimiterspace} 2}} (j^{ - 2} )_{0^ + }$$ configuration with maximum alignment of the angular momenta. The total two-particle core polarization due to theh 9/2 andi 13/2 protons and theg 9/2 neutron was found to be −68±20 keV as compared to −125±18 keV for the 29/2+ isomeric state of the $$\pi h_{{9 \mathord{\left/ {\vphantom {9 2}} \right. \kern-\nulldelimiterspace} 2}}^2 i_{1{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} v(j^{ - 2} )_{0^ + }$$ configuration in209At, which only differs by ag 9/2 neutron. This observation indicates an isospin effect in the two-particle core polarization, which is also supported by recent discoveries of core-excited high-spin levels in208Bi using (d, α)-reactions. Thus in the orbits concerned, a proton-proton pair seems to have a much larger quadrupole polarization effect than a neutron-proton pair.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01422102