Publication

Transition Probabilities and Quadrupole Deformation Moments Measured in 108Cd

Nuclear physics

Nuclear Physics A 568 (1994) 306.

Authors:

I. Thorslund, C. Fahlander, J. Nyberg, M. Piiparinen, R. Julin, S. Juutinen, A. Virtanen, D. Müller, H. Jensen, M. Sugawara

Summary

The study employs the recoil-distance method (RDM) to measure lifetimes of high-spin states in ¹⁰⁸Cd populated via the ¹⁰⁰Mo(¹²C,4nγ) reaction.

Key findings include:

  • B(E2) Values: Enhanced quadrupole transitions (B(E2) ≈ 10–30 W.u.) confirm collective rotational structures in multiple bands. For example, the 10⁺ → 8⁺ transition in Band 7 yields B(E2) = 25 W.u., while transitions in negative-parity bands (Bands 1–4) show moderate collectivity.
  • Deformation Parameters: Experimental quadrupole deformations (β₂ ≈ 0.15–0.17) align with Total Routhian Surface (TRS) predictions (β₂ ≈ 0.20–0.25), supporting prolate deformation. Band 10, linked to a ν(h₁₁/₂)² configuration, exhibits larger B(E2) values (25 W.u.) compared to other bands.
  • Configuration Insights: Weak B(E1) transitions (10⁻⁵–10⁻⁶ W.u.) from the 10⁺ state to negative-parity bands suggest partial octupole collectivity or νg₇/₂ contributions. The 8⁺ state in Band 10 is proposed to involve a ν(h₁₁/₂)² ⊗ π(g₉/₂)⁻² configuration.

The study underscores the interplay between collective rotations and single-particle excitations near the N=60 neutron shell closure, validating TRS models for deformation trends.

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