[en] Nuclear resonant photon scattering from ^206207208Pb and ²⁰⁹Bi was measured over excitation regions from 4 MeV to the neutron thresholds with bremsstrahlung beams with endpoint energies of 7.0, 7.5, 7.6, 8.5, and 10.4 MeV. Photons scattered from enriched targets of the lead isotopes and from bismuth were observed with a Ge(Li) detector. Energies and values of gGAMMA₀²/GAMMA were determined from measurements at 127⁰ for many levels not previously observed in photon scattering experiments. Spins of levels in ²⁰⁶Pb and ²⁰⁸Pb were determined from angular distribution measurements. Ground-state branching ratios for seven transitions in ²⁰⁸Pb were obtained from a self-absorption experiment. The results are compared with results from earlier spectroscopic studies and from average photon scattering cross section measurements. The spectra of ²⁰⁷Pb and ²⁰⁹Bi are discussed in terms of the excitations of the ²⁰⁸Pb core

[en] The fractional decay branch in the EC decay of ⁷Be leading to the first excited state of ⁷Li has been measured. ⁷Be ions from a beam produced by a tandem Van de Graaff accelerator were implanted into a surface-barrier detector; the decay γ rays were then counted using a well-shielded Ge(Li) detector of known absolute efficiency. The resulting decay branch, (10.10 +- 0.45)%, is in good agreement with previously published values and in strong disagreement with a recent measurement

No abstract available

[en] A bremsstrahlung photon beam from electrons with end-point energies of 7.66 and 10.37 MeV was used for photoexciting levels in ²³Na. Values of gGAMMA₀²/GAMMA and gGAMMA₀ of 22 levels below 10 MeV were obtained using scattering and self-absorption measurements. The values for 7 levels are reported for the first time. The temperature variation of the scattering cross section was measured at T = 300 K and T = 78 K to study in some detail the effective temperature T/sub e/ of metallic ²³Na. The results of the total B(M1up-arrow) strength of T = 1/2 levels below 9 MeV were found to be in excellent agreement with the large-scale shell-model calculations

[en] Nuclear resonance fluorescence experiments with unpolarized and linearly polarized bremsstrahlung and high-resolution Ge(Li) detectors have yielded model-independent values of magnetic dipole excitation strengths to highly excited states in sup(20,) ²²Ne, sup(24,) ²⁶Mg, sup(28,) ³⁰Si, and sup(32,) ³⁴S. The measured B(M1) values are quenched relative to the j-j limit of the shell model, but are in general agreement with predictions of recent shell-model calculations which treat intra-sd-shell configuration mixing completely. (orig.)