Publication

Two-to-One Phonon E3 Transition Strength in 148Gd

Nuclear physics

Physical Review Letters 70 (1993) 150

Authors:

M. Piiparinen, P. Kleinheinz, J. Blomqvist, A. Virtanen, A. Atac, D. Müller, J. Nyberg, T. Ramsoy, G. Sletten

Summary

The study measured the lifetime of the 6⁺ state at 3.981 MeV in ¹⁴⁸Gd using a plunger experiment, determining a B(E3) strength of 77(11) W.u. for the 6⁺ → 3⁻ transition.

This confirms the double-octupole phonon character of the 6⁺ state. Observed deviations from harmonic vibrational predictions (e.g., energy splitting and B(E3) reduction) stem from Pauli exclusion effects between nucleons in the two-phonon excitation.

The work highlights the role of proton and neutron in-shell Δj=3 excitations in shaping octupole collectivity, critical for understanding vibrational modes in open-shell nuclei.

Use of Internal References for Assessing CT Density Measurements of the Pelvis as Replacement for Use of an External Phantom

The study evaluated whether internal fat/muscle references could replace external phantoms for CT density calibration in 50 patients with metal-on-metal hip replacements.

Key findings:

  • HU Agreement: Internal fat (−91.5 ± 7.0 HU) and muscle (59.2 ± 6.2 HU) references showed excellent correlation with phantom values (fat: −90.9 ± 7.8 HU; muscle: 60.0 ± 7.2 HU), with intra-class correlation coefficients of 0.90 (fat) and 0.84 (muscle).
  • Clinical Utility: Internal calibration eliminated the need for external phantoms, enabling retrospective analysis of CT scans without additional hardware.
  • Implications: This method allows standardized density measurements across patients and timepoints, enhancing opportunistic use of clinical CT data.

The study concludes that internal references are equally reliable for CT density measurements, streamlining clinical workflows.

Go back