P. M. S. Lesser

Bremsstrahlung from /sup 16/O+p near the 2. 66-MeV resonance

The proton-oxygen bremsstrahlung cross sections have been measured at a bombarding energy of 2.74 MeV and at a scattering angle of 155/sup 0/, for photon energies between 40 and 200 keV. The measured spectrum agrees well with the prediction of the Feshbach-Yennie approximation.

Properties of high-spin states in Nb91 and Zr91 via Li6-induced reactions

The properties of high-spin states in /sup 91/Nb and /sup 91/Zr have been studied with the /sup 88/Sr(/sup 6/Li, 3n)/sup 91/Nb and /sup 88/Sr(/sup 6/Li, p2 n)/sup 91/Zr reactions. In-beam measurements with Ge(Li) and Si(Li) detectors of ..gamma..-ray excitation functions, ..gamma..-..gamma.. coincidences, ..gamma..-ray angular distributions, and pulsed beam-..gamma.. timing spectra were made to establish decay schemes, level energies, spin-parity assignments, ..gamma..-ray multipolarities, and isomeric lifetimes. All of the high-spin states involving the ..pi..1g/sub 9///sub 2/, ..pi..2p/sub 1///sub 2/, and ..nu..2d/sub 5///sub 2/ orbitals as well as other more complicated states were identified. In particular, the theoretically predicted isomeric states in /sup 91/Nb and /sup 91/Zr were found: the vertical-bar (1g/sub 9///sub 2/)/sup 2/2p/sub 1///sub 2/, 17/2/sup -/> state in /sup 91/Nb is at 2035 keV with a tau = 5.42 +- 0.18 ..mu..sec, and vertical-bar (1g/sub 9///sub 2/) /sup 2/2d/sub 5///sub 2/, 21/2/sup +/> state in /sup 91/Zr is at 3167 keV with a tau = 6.28 +- 0.20 ..mu..sec. The experimental energy levels and B (E2) values (E2 effective charges) obtained for these nuclei as well as those of other N = 50 and 51 nuclei are compared with recent theoretical work of Gloeckner et al. (AIP)

High-spin states in Zr92

High-spin states have been investigated with the /sup 88/Sr(/sup 7/Li, p2n)/sup 92/Zr reaction by ..gamma..-..gamma.. coincidence, ..gamma..-ray angular distribution, and pulsed beam-..gamma.. timing measurements with Ge(Li) detectors. Decay schemes, level energies, and spin-parity information were obtained for /sup 92/Zr from the data. The high-spin states involving the (..pi..1g/sub 9///sub 2/)/sup 2/(..nu..2d/sub 5///sub 2/)/sup 2/ configuration were identified, with the (12/sup +/) member being at 4947 keV. Tentative identification of the members of the (..pi..1g/sub 9///sub 2/..pi..2p/sub 1///sub 2/)(..nu..2d/sub 5///sub 2/)/sup 2/ configuration has also been made. The observed experimental levels in /sup 92/Zr are compared with recent theoretical calculations. (AIP)