Lifetime measurements on the high-spin rotational bands in Nd-133 have been carried out by the Doppler-shift attenuation method using the GASP array. The Nd-133 nuclei were populated in the Pd-104(S-32, 2pn) reaction at a bombarding energy of 135 MeV. The Doppler-broadened line shapes were analyzed for Au-backed and Gd-backed targets. Values of Q(t) = 4.7(5), 5.6(5), and 7.4(4) eb have been determined for the mean transitional quadrupole moments of the ground-state band, the negative-parity band involving the neutron h(9/2)/f(7/2) intruder orbitals, and the band built on the neutron [660]1/2(+) intruder orbital, respectively. The presently determined quadrupole moments are compared with those of the low-spin members of the bands derived elsewhere from recoil distance method measurements. The observed polarizing effects of the neutron intruder orbitals are compared with cranked shell model predictions. [S0556-2813(99)05308-X].

High-spin states in doubly odd Re-176 were investigated by means of in-beam gamma-ray spectroscopy techniques using the multidetector array GASP. Excited states of Re-176 were populated using the Ho-165(O-16,5n) reaction at a beam energy of 101 MeV. Seven rotational bands have been observed and their configurations have been discussed. Alignments, band crossing frequencies, and electromagnetic properties have been analyzed in the framework of the cranking model. Signature inversion phenomena in the pi h(11/2)xvi(13/2) and pi h(9/2)xvi(13/2) structures are discussed. In the latter case signature inversion is traced to a large repulsive matrix element of the p - n force acting in the maximally aligned J = 11 state. [S0556-2813(99)04702-0].

High-spin states in doubly odd ${}^{176}\mathrm{Re}$ were investigated by means of in-beam $\ensuremath{\gamma}$-ray spectroscopy techniques using the multidetector array GASP. Excited states of ${}^{176}\mathrm{Re}$ were populated using the ${}^{165}\mathrm{Ho}{(}^{16}\mathrm{O},5n)$ reaction at a beam energy of 101 MeV. Seven rotational bands have been observed and their configurations have been discussed. Alignments, band crossing frequencies, and electromagnetic properties have been analyzed in the framework of the cranking model. Signature inversion phenomena in the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$ and $\ensuremath{\pi}{h}_{9/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$ structures are discussed. In the latter case signature inversion is traced to a large repulsive matrix element of the $p\ensuremath{-}n$ force acting in the maximally aligned $J=11$ state.

Ir-186 has been restudied through the Hf-180(B-11,Sn) reaction at 65 MeV using in-beam gamma-ray and conversion-electron spectroscopy. The unfavored component of the doubly decoupled band was established and shown to be consistent with a description in terms of the pi(9/2)circle times nu[<(411)over tilde> 1/2,3/2] structure, i.e., the coupling of an aligned proton and a neutron pseudospin doublet.

High-spin states in Lu-162 and Lu-164 have been studied by means of in-beam gamma-ray spectroscopy techniques using the multidetector array GASP. The excited states have been populated through the La-139(Si-28,5n)Lu-162 and La-139[(29(30))Si,4(5)n]Lu-164 reactions. Level schemes were constructed for both nuclei. Configurations for the rotational bands have been discussed. Alignments, band crossing frequencies, and B(M1)/B(E2) ratios have been analyzed in the framework of the cranking model. The systematic evolution of the signature inversion in the pi h(11/2)x nu i(13/2) structure is reviewed.

High-spin states in ${}^{162}$Lu and ${}^{164}$Lu have been studied by means of in-beam $\ensuremath{\gamma}$-ray spectroscopy techniques using the multidetector array GASP. The excited states have been populated through the ${}^{139}\mathrm{La}{(}^{28}\mathrm{Si}{,5n)}^{162}$Lu and ${}^{139}\mathrm{La}{[}^{29(30)}\mathrm{Si},4(5)n{]}^{164}$Lu reactions. Level schemes were constructed for both nuclei. Configurations for the rotational bands have been discussed. Alignments, band crossing frequencies, and $B(M1)/B(E2)$ ratios have been analyzed in the framework of the cranking model. The systematic evolution of the signature inversion in the $\ensuremath{\pi}{h}_{11/2}\ensuremath{\bigotimes}\ensuremath{\nu}{i}_{13/2}$ structure is reviewed.

A 4 pi detection system sensitive to light charged particles is being developed at the Laboratori Nazionali di Legnaro (LNL) for the study of the reaction mechanisms produced in heavy ion collisions at energies up to 20 AMeV. The 8 pi LP apparatus is a telescope assembly characterized by large solid angle (90% of 4 pi) and high granularity (262 modules). Particle identification at low energy is obtained by combining Delta E-E, TOF and PSD techniques. Each telescope is made of a 300 mu m passivated silicon detector and a 15 mm (or 5 mm) CsI(TI) crystal with photodiode readout. Thresholds for particle identification range from 1 MeV for protons and 3 MeV for alpha particles to about 2-3 AMeV for C ions. A low-cost trigger and readout bus system has been developed to cope with the large number of parameters and the high counting rate. The system will be fully operational for experiments in the Summer of 1997.

The structure of the high spin states above the 28(-) isomer in the odd-odd Ho-152 nucleus was investigated using the GASP gamma-ray spectrometer coupled to the recoil mass spectrometer CAMEL. The Ho-152 nucleus was populated through the Sn-120(Cl-37,5n) fusion reaction at a beam energy of 187 MeV. A complex level scheme above that isomer was established up to an excitation energy of 13 MeV and I approximate to 40HBAR. No rotational bands were observed.

Lifetimes of states of the highly-deformed (HD) band in 137Nd have been measured using the Doppler shift attenuation method. A line-shape analysis has been carried out for individual states, resulting in transition quadrupole moments which decrease with increasing spin. This represents the first confirmation of previous total routhian surface (TRS) calculations that predicted a drift towards positive γ values of the HD minimum (at essentially constant β deformation). The lifetime data show a rather modest deformation of the HD band structure, indicating a softening of the nuclear potential at HD shape.

High spin rotational bands in 162 Lu and 164 Lu have been studied through the 139 La( 28 Si,5n) and 139 La( 29(30) Si,4(5)n) reactions respectively. For both nuclei the yrast sequence which is associated with the πh 11/2 ⊗νi 13/2 configuration shows the signature inversion feature.

Rotational structures in 134Nd have been investigated using the GASP array via the 110Pd(28Si,4n) reaction at 130 MeV. Each of the observed high-spin bands experiences a change in structure, that involves the promotion of a particle from the N = 4 into the N = 6 orbital. The adiabatic character of the corresponding bandcrossings, indicated by vertical or gradual upbendings of the aligned angular momentum, gives evidence of a sizeable mixing between the N = 4 and N = 6 configurations. The successive occupation of the first and second N = 6 intruder orbitals indicates that, at difference from the paired alignment exhibited by normal-deformed nuclei between the ground-state band and the S-band, in highly-deformed nuclei, the unpaired alignment is the favored mechanism for generating high angular momenta.

Alpha particle spectra in coincidence both with normal deformed (ND) and superdeformed (SD) bands of 150Tb have been measured using the reaction 120Sn(37Cl,α3n) at 187 MeV bombarding energy. A clear difference is observed between the two spectra, that in coincidence with the SD states being shifted to lower energies. This effect is understood in terms of different angular momentum regions from which the ND and SD states orginate. The standard statistical model fails to describe the angular momentum dependence of the alpha particle energies.

The \ensuremath{\gamma} cascades feeding into low-K and high-K bands in ${}^{163}$Er are investigated analyzing variances and covariance of the spectrum fluctuations. From a large data set of 1${0}^{9}$ triple coincidences, \ensuremath{\gamma}-\ensuremath{\gamma} coincidence spectra gated by resolved low-lying rotational bands are analyzed. Low-K bands are found to be fed by a much larger effective number of cascades than high-K bands. The covariance between pairs of gated spectra shows that the cascades feeding low-K bands are different from those feeding the high-K bands. The persistence of the K-selection rules for the excited rotational bands within the angular momentum region $30\ensuremath{\Elzxh}\ensuremath{\le}I\ensuremath{\le}40\ensuremath{\Elzxh}$ is suggested as explanation.

The hyperdeformed ridge structure recently observed in the reaction of 187 MeV 37Cl on 120Sn has been confirmed in a new proton-γ coincidence experiment at the GASP spectrometer and assigned to the nucleus 152Dy. Proton spectra have been measured in coincidence with γ-rays belongings to the different structures in 152Dy (oblate, prolate, super- and hyper-deformed). The deformation of the final evaporation residue affects only weakly the proton evaporation from the compound nucleus. Evidence has been found that the energy of the protons in coincidence with the hyperdeformed structure is larger than expected. This effect is discussed in the framework of the fission-evaporation competition.

Very proton rich nuclei in the A approximate to 100 region have been investigated using the GASP array coupled with the Recoil Mass Spectrometer (RMS) and the GASP Si-ball. High-spin states of Sn-105 and In-103 nuclei formed with the reaction Ni-58 + Cr-50 at 210 MeV have been investigated up to approximate to 10 and 7 MeV of excitation energy respectively. We have confirmed the known excited states for both nuclei and extended to higher spin the level scheme. The experimental level schemes are compared with shell model calculations.

Very proton rich nuclei in the A ≈ 100 region have been investigated using the GASP array coupled with the Recoil Mass Spectrometer (RMS) and the GASP Si-ball. High-spin states of 105Sn and 103,105In nuclei formed with the reaction 58Ni + 50Cr at 210 MeV have been investigated up to ≈ 10 and 7 MeV of excitation energy respectively. We have confirmed the known excited states for both nuclei and extended to higher spin the level scheme. The experimental level schemes are compared with shell model calculations.

A g-factor measurement in the superdeformed band of 133Nd has been performed by applying the transient field method in coincidence mode with the multidetector array GASP. The 133Nd nuclei were populated by the 104Pd(32S,2pn) reaction at a bombarding energy of 135 MeV. Polarized Gd has been used as ferromagnetic host. A mean g-factor of g = 0.31(8) has been determined at the Iπ = 412+ superdeformed state. The experimental value is compared with theoretical predictions and supports the assignment of the superdeformed band to the ν[660]12+ Nilsson intruder orbital.