Nuclear moments of germanium isotopes near N=40

A. Kanellakopoulos, X. F. Yang, M. L. Bissell, M. L. Reitsma, S. W. Bai, J. Billowes, K. Blaum, A. Borschevsky, B. Cheal, C. S. Devlin, R. F. Garcia Ruiz, H. Heylen (+15 others)
2020 Physical Review C  
Collinear laser spectroscopy measurements were performed on 69,71,73 Ge isotopes (Z = 32) at ISOLDE-CERN. The hyperfine structure of the 4s 2 4p 2 3 P 1 → 4s 2 4p5s 3 P o 1 transition of the germanium atom was probed with laser light of 269 nm, produced by combining the frequency-mixing and frequency-doubling techniques. The hyperfine fields for both atomic levels were calculated by using state-of-the-art atomic relativistic Fockspace coupled-cluster method. A new 73 Ge quadrupole moment was
more » ... ermined from these calculations and previously measured precision hyperfine parameters, yielding Q s = −0.198(4) b, in excellent agreement with the literature value from molecular calculations. The moments of 69 Ge have been revised: μ = +0.920(5) μ N and Q s = +0.114(8) b, and those of 71 Ge have been confirmed. The experimental moments around N = 40 are interpreted with large-scale shell-model calculations using the JUN45 interaction, revealing rather mixed wave-function configurations, although their g factors are lying close to the effective single-particle values. Through a comparison with neighboring isotones, the structural change from the single-particle nature of nickel to deformation in germanium is further investigated around N = 40.
doi:10.1103/physrevc.102.054331 fatcat:ls2r5ehzc5bbpb5yhdxds6rhqq