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The first feasibility study of an α-particle capture reaction in inverse kinematics at energies relevant to the p process was performed at the Wien Filter of the LISE spectrometer at GANIL. Hereby, the 4He(78Kr,γ)82Sr reaction was investigated using as target an 4He-implanted thin Al foil. The analysis of the data has shown that the determination of (α,γ) reaction cross sections at rather low energies around 2 MeV/u in inverse kinematics is indeed feasible regarding the high rejection rate of the primary beam, which in the present work was better than a factor of 109. However, the expected position of the recoils of interest was completely masked by particles of currently unknown origin that could hardly be attributed to scattering of the primary beam. The most probable explanation for the origin of these 'pollutants' could be microscopic dust particles of 10 μm diameter and less, that are extremely difficult to avoid in standard experimental conditions. Hence, the use of a gas-jet target instead of a solid one is compulsory. [ABSTRACT FROM AUTHOR]

The investigation of the limits of nuclear existence is fundamental to the understanding of nuclear forces and structure. The limits of binding for very neutron-rich nuclei and the location of the neutron dripline are established experimentally only for the lightest elements. We report on the discovery of the new neutron-rich isotopes 40Mg, 42,43Al, and 44Si. These rare isotopes were produced at the National Superconducting Cyclotron Laboratory by fragmentation of a 141 MeV/u 48Ca beam on a tungsten target. The combination of the A1900 fragment separator together with the analysis beam line of the S800 spectrograph provided a two-stage fragment separation with exceptional selectivity. The observation of the odd-odd nucleus 42Al, which was predicted to be unbound by FRDM [1] and HFB-8 [2] models, is the first indication that the neutron drip line may be located significantly further towards heavier isotopes in this mass region than it is currently believed. [ABSTRACT FROM AUTHOR]

The decay properties of rp-process nuclei in the vicinity of 100Sn have been studied at the National Superconducting Cyclotron Laboratory (NSCL). The measured β-decay half-life for 100Sn is 0.55-0.31+0.70 s, in agreement with a previous measurement. In 98In, the β-decay of the ground state plus that of a long lived isomer were observed with half-lives of 47(13) ms and 0.66(40) s respectively. The half-life of 96Cd, measured for the first time, is 1.03-0.21+0.24 s; however, the existence of a predicted isomeric state in this nucleus could not be confirmed. Additionally, a gamma cascade de-exciting a μ-isomer in the odd-odd nucleus 96Ag was observed. The implications of the measured half-life of 96Cd on the calculated rp-process final abundances are discussed. [ABSTRACT FROM AUTHOR]

S3 (Super Separator Spectrometer) is a device designed for experiments with the very high intensity stable beams of LINAG, the superconducting linear accelerator of GANIL, which will be built in the framework of SPIRAL2. These beams, which will provide ions with A/Q = 3 in SPIRAL2 phase one, can reach intensities up to 1mA for light ions, A<50. These unprecedented intensities open new opportunities in several physics domains, e.g. super-heavy and very-heavy nuclei, spectroscopy at and beyond the drip line, isomers and ground state properties, multi-nucleon transfer and deep-inelastic reactions. An international collaboration has been formed to propose physics experiments and develop technical solutions for this new instrument. [ABSTRACT FROM AUTHOR]

We review our recent experiments on interaction-induced effects in a gas of Rydberg atoms excited from a laser-cooled rubidium cloud. The van-der-Waals interaction between a pair of Rydberg atoms separated as far as 100,000 Bohr radii features two important effects: Spectral broadening of the resonance lines and suppression of excitation with increasing Rydberg density. The line broadenings are interpreted in terms of level shifts of Rydberg pairs due to their interaction. The density-dependent suppression of excitation marks the onset of an interaction-induced local blockade. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]