H.-Q. Jin

Forking and Unusual Decay Out of Superdeformed Bands in 83Zr

Two superdeformed (SD) bands extending over eight to eleven transitions have been identified in Zr-83, The quadrupole moment of the more intense band was determined by the Residual Doppler Shift Method and is consistent with a quadrupole deformation of beta(2) approximate to 0.5. The large quadrupole moment and population intensity of the yrast SD band (approximate to 5%) in Zr isotopes relative to their isotones in Sr and Y nuclei suggest the presence of a large SD shell gap at proton number Z = 40, At the decay-out points, the Routhians of the SD bands reapproach that of the positive parity normally-deformed states which may be the reason why both of these bands feed mainly (approximate to 85%) into the positive-parity yrast band.

Transition energy staggering and band interaction in rare-earth nuclei☆

Abstract Staggering of the transition energies Eγ and moments of inertia J (2) for rotational bands in rare-earth nuclei is investigated by means of the higher order derivatives ΔnEγ (n = 2,3,4). It is shown that these (ΔI = 2) staggering effects in the normally deformed bands are related to band interaction. The band interaction picture is also applied to staggering effects in superdeformed bands.

Superdeformed Bands in 80Sr and the Evolution of Deformation in Sr Isotopes

Four superdeformed bands are reported in Sr-80, extending known superdeformation in the Sr-38 series down to N = 42. The characteristics of these bands are discussed. Residual Doppler shifts were measured and average transition quadrupole moments (Q(t)) inferred for these new bands, These Q(t) values are compared to Q(t) values obtained for previously identified superdeformed bands in Sr81-83. The low Q(t) of 2.7(-0.6)(+0.7) eb obtained for the yrast band in Sr-80 indicates a reduction in the deformation of yrast superdeformed bands in the series Sr80-83 with decreasing N, and possibly the onset of triaxiality in superdeformed shapes

Search for Hyperdeformation in 146,147Gd

A search was undertaken to look for evidence of hyperdeformation in {sup 146,147}Gd. Three experiments employing Gammasphere for gamma-ray detection coupled with the Microball for channel selection via charged particle detection were carried out with increasing detection sensitivity and statistics. No definitive evidence for band structures that could be assigned to hyperdeformation could be found. Candidates previously reported are shown not to have properties consistent with a band structure. {copyright} {ital 1996 The American Physical Society.}

Multiple Superdeformed Bands In Sr, Y, And Zr Nuclei

Multiple superdeformed bands in the nuclei 80–83Sr, 82–84Y, and 83,84Zr have been studied in a backed‐target experiment using the Gammasphere and Microball detector arrays. For 15 bands in these nuclei, average transition quadrupole moments (Qt) have been measured accurately. Among those are two pairs of “isospectral” bands and the Qt values obtained in each case are nearly identical. The measured Qt values and dynamical moments of inertia place stringent conditions on configuration assignments for the bands obtained from mean field calculations.

Search for hyperdeformation in {sup 146,147}Gd

A search was undertaken to look for evidence of hyperdeformation in {sup 146,147}Gd. Three experiments employing Gammasphere for gamma-ray detection coupled with the Microball for channel selection via charged particle detection were carried out with increasing detection sensitivity and statistics. No definitive evidence for band structures that could be assigned to hyperdeformation could be found. Candidates previously reported are shown not to have properties consistent with a band structure. {copyright} {ital 1996 The American Physical Society.}