PubMed Health⌕ Search

Biomedical subjects

W Reviol

Publications and source records attributed to W Reviol.

At least 19 recordsLinked to original sources

58Ni: an unpaired band crossing at new heights of angular momentum for rotating nuclei.

High-spin states in 58Ni have been investigated by means of the fusion-evaporation reaction 28Si(32S, 2p)58Ni at 130 MeV beam energy. Discrete-energy levels are observed in 58Ni at record-breaking 42 MeV excitation energy and angular momenta in excess of 30h. The states form regular rotational bands with unprecedented high rotational frequencies. A comparison with configuration dependent cranked Nilsson-Strutinsky calculations reveals an exceptional two-band crossing scenario, the interaction strength of which is strongly shape dependent.

Journal Article↗

Evidence for nontermination of rotational bands in 74Kr.

Three rotational bands in 74Kr were studied up to (in one case one transition short of) the maximum spin I(max) of their respective single-particle configurations. Their lifetimes have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments reveal a modest decrease, but far from a complete loss of collectivity at the maximum spin I(max). This feature, together with the results of mean field calculations, indicates that the observed bands do not terminate at I = I(max).

Journal Article↗

Superdeformation in the doubly magic nucleus (40)(20)Ca(20).

A rotational band with seven gamma-ray transitions between states with spin 2 Planck's constant and 16 Planck's constant has been observed in the doubly magic, self-conjugate nucleus (40)(20)Ca(20). The measured transition quadrupole moment of 1.80(+0.39)(-0.29)eb indicates a superdeformed shape with a deformation beta(2) = 0.59(+0.11)(-0.07). The features of this band are explained by cranked relativistic mean field calculations to arise from an 8-particle 8-hole excitation.

Journal Article↗

Half-life measurement for the rp-process waiting point nuclide 80Zr

X-ray bursts have been suggested as a possible site for the astrophysical rp-process. The time scale for the process is governed by beta-decay half-lives of several even-even N = Z waiting point nuclei, in particular, N = Z = 40 80Zr. A 4.1(+0.8/-0.6)-s beta(+)/EC half-life for 80Zr was determined by observing delayed 84-keV gamma rays depopulating a T(1/2) = 4-&mgr;s isomer at 312 keV in the daughter 80Y. As this half-life is lower than many previously predicted values, the calculated excessive production of A = 80 nuclides in astrophysical x-ray burst scenarios is reduced, and less extreme conditions are necessary for the production of heavier nuclides.

Journal Article↗