The Measurement of Magnetic Moments of Excited States in Palladium, Tungsten, and Thulium Nuclei

[摘要] The perturbed gamma - gamma angular correlation technique hasbeen used to measure the magnetic moments of several nuclear excitedstates. The magnetic moment of the second excited 2⁺ state in¹⁰⁶Pd has been measured to be μ = 0.74 ± 0.14 nm, in good agreementwith the interpretation of that state as a two-phonon quadrupolevibration about spherical equilibrium. The magnetic moment of thetwo-quasiparticle 2^- state at 1289 keV in ¹⁸²W has been measured tobe μ = 1.04 ± 0.24 nm) in poor agreement with the predictions ofthe "strong-coupling" approximation. The probable origin of thediscrepancy is discussed. The following magnetic moments in odd-massthulium nuclei have been measured: the 5/2⁺ level at 118.2 keV in¹⁶⁹Tm with μ 0.79 ± 0.08 nm; the 7/2⁺ level at 138.9 keV in ¹⁶⁹Tmwith μ = 1.33 ± 0.07 nm; the 5/2⁺ level at 116.7 keV in ¹⁷¹Tm withμ 0.81 ± 0.37 nm; and the 7/2⁺ level at 129.1 keV in ¹⁷¹Tm withμ = 1.44 ± 0.14 nm. In addition, the multipole mixing amplitude forthe 109.8 keV transition in ¹⁶⁹Tm has been measured to beδ(E2/M1) = -0.15 ± 0.02) and the crossover-to-cascade transitionintensity ratios for the 5/2⁺(116.7 keV) and 7/2⁺(129.1 keV) statesin ¹⁷¹Tm have been measured to be I_γ (5/2 → 1/2)/I_γ(5/2 → 3/2) =0.115 ± 0.005 and I_tot(7/2 → 3/2)/I_tot(7/2 → 5/2) = 3.22 ± 0.58,respectively. The results of the measurement in the thulium nucleihave been us ed in conjunction with other data to determine the parametersin the rotational model description of the nuclei. Themagnetic parameters are interpreted in terms of transverse andlongitudinal spin polarization effects; where only qualitativeagreement with theory is found. A correction to the rotational modelpredictions of electric quadrupole transition rates is also discussed.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics