The occurence of exotic shapes in light N=Z alpha-like nuclei is investigated for 24Mg+12C and 32S+24Mg. Various approaches of superdeformed and hyperdeformed bands associated with quasimolecular resonant structures with low spin are presented. For both reactions, exclusive data were collected with the Binary Reaction Spectrometer in coincidence with EUROBALL IV installed at the VIVITRON Tandem facility of Strasbourg. Specific structures with large deformation were selectively populated in binary reactions and their associated $gamma$-decays studied. The analysis of the binary and ternary reaction channels is discussed.
The gamma-decay properties of 24Mg excited states are investigated in the inverse reaction 24Mg+12C at E(24Mg) = 130 MeV. At this energy the direct inelastic scattering populates a 24Mg* energy region where 12C+12C breakup resonances can occur. Very exclusive data were collected with the Binary Reaction Spectrometer (BRS) in coincidence with EUROBALL installed at the VIVITRON Tandem facility of the IReS at Strasbourg. The experimental detection system is decribed and preliminary results of binary reaction coincid data are presented.
Charged particle and gamma decays in 24Mg* are investigated for excitation energies where quasimolecular resonances appear in 12C+12C collisions. Various theoretical predictions for the occurence of superdeformed and hyperdeformed bands associated with resonance structures with low spin are discussed within the measured 24Mg* excitation energy region. The inverse kinematics reaction 24Mg+12C is studied at E_lab(24Mg) = 130 MeV, an energy which enables the population of 24Mg states decaying into 12C+12C resonant break-up states. Exclusive data were collected with the Binary Reaction Spectrometer in coincidence with EUROBALL IV installed at the VIVITRON Tandem facility at Strasbourg. Specific structures with large deformation were selectively populated in binary reactions and their associated gamma decays studied. Coincident events associated with inelastic and alpha-transfer channels have been selected by choosing the excitation energy or the entry point via the two-body Q-values. The analysis of the binary reaction channels is presented with a particular emphasis on 24Mg-gamma, 20Ne-gamma and 16O-gamma coincidences. New information (spin and branching ratios) is deduced on high-energy states in 24Mg and 16O, respectively.
Charged particle and gamma decays in light alpha-like nuclei are investigated for 24Mg+12C. Various theoretical predictions for the occurence of superdeformed and hyperdeformed bands associated with resonance structures with low spin are presented. The inverse kinematics reaction 24Mg+12C is studied at Elab(24Mg) = 130 MeV. Exclusive data were collected with the Binary Reaction Spectrometer in coincidence with EUROBALL IV installed at the VIVITRON Tandem facility at Strasbourg. Specific structures with large deformation were selectively populated in binary reactions and their associated gamma decays studied. Coincident events from $alpha$-transfer channels were selected by choosing the excitation energy or the entry point via the two-body Q-values. The analysis of the binary reaction channels is presented with a particular emphasis on 20Ne-gamma and 16O-gamma coincidences.
Differential cross sections and analyzing powers for elastic scattering from, and for inelastic proton scattering to a set of $2^+_1$ states in, ${}^{12}$C, ${}^{20}$Ne, ${}^{24}$Mg, ${}^{28}$Si and ${}^{40}$Ca, and for a set of energies between 35 to 250 MeV, have been analyzed. A $g$-folding model has been used to determine optical potentials and a microscopic distorted wave approximation taken to analyze the inelastic data. The effective nucleon-nucleon interactions used to specify the optical potentials have also been used as the transition operators in the inelastic scattering processes. Shell and large space Hartree-Fock models of structure have been used to describe the nuclear states.
Gamow-Teller transitions from 24Mg to 24Na were studied via the (t,3He) reaction at 115 AMeV using a secondary triton beam produced via fast fragmentation of 150 AMeV 16O ions. Compared to previous (t,3He) experiments at this energy that employed a primary alpha beam, the secondary beam intensity is improved by about a factor of five. Despite the large emittance of the secondary beam, an excitation-energy resolution of ~200 keV is achieved. A good correspondence is found between the extracted Gamow-Teller strength distribution and those available from other charge-exchange probes. Theoretical calculations using the newly developed USDA and USDB sd-shell model interactions reproduce the data well.