S Ternier

Influence of particle-core coupling on the quadrupole moment of 8+ isomers in even-even Po isotopes

Abstract The ratio of the quadrupole moment of the 8 + isomers in 202 Po and 204 Po has been measured in a Pt host using the level mixing spectroscopy method: Q( 202 Po ) Q( 204 Po ) = 1.06(13) . The increase of the Po(8 + ) quadrupole moments with decreasing neutron number can be explained by explicitly taking into account the interaction between the |π1 h 9 2 2 〉 two-proton configuration and the core quadrupole vibrational excitations of the underlying even-even Pb core. A very good quantitative agreement is observed, indicating that core polarization near the Z = 82, N = 126 closed-shell region can be understood by particle-core coupling.

Study of the static quadrupole moment of the K=35/2 isomer in 179W

The quadrupole interaction frequency of the high-K five-quasiparticle isomer in W-179 implanted in a Tl host at a temperature of 473 K has been determined using the LEMS method. A value of 65.7(7.5) MHz has been found.

Measuring Quadrupole Moments in a Recoil-Shadow Geometry Using the Lems Method

The applicability of the LEMS technique using a recoil-shadow configuration, is demonstrated. As a test case the \( ^{69}Ge({I^\pi } = {\frac{9}{2}^ + },\tau = 4\mu s,\mu = - 1.0011n.m) \) released out of a natFe foil with a recoil velocity of 1.6(5)%c has been studied. The magnetic field induced by the atomic electrons at the place of the 69Ge nucleus is found to be 2200(600)T.

Quadrupole frequency measurements using defect associated electric field gradients in cubic host materials

Abstract Level Mixing Spectroscopy (LEMS) can be used to determine nuclear quadrupole moments. In this paper it is shown how LEMS can be applied to nuclei implanted in a cubic lattice. In this case the quadrupole interaction is due to electric field gradients produced by defects. The method has been illustrated by measuring quadrupole moments of 202–204 Po isomers produced in nat Pt( 12 C, 4n) and nat Pt( 13 C, 5n) reactions, the (natural) Platinum serving as a host material. The result could be analysed with the assumption of two different defect associated sites, making up for about 80% of the total site population. The experimental ratio Q ( 202 Po,8 + )/ Q ( 204 Po,8 + ) is in agreement with the systematics in the lead region. LEMS measurements in cubic crystals provide another nuclear method for the study of nuclear quantities or solid state parameters.