105 research outputs found
Study of the N=50 major shell effect close to Ni : First evidence of a weak coupling structure in Ge and three-proton configuration states in Ga
New levels were attributed to Ga and
Ge which were fed by the -decay of their respective
mother nuclei Zn and Ga produced by
fission at the "PARRNe" ISOL set-up installed at the Tandem accelerator of the
Institut de Physique Nucl\'eaire, Orsay. We show that the low energy structure
of Ga and Ge can easily be explained
within the natural hypothesis of a strong energy gap at N=50 and a doubly-magic
character for Ni.Comment: 2 pages, pdf file, To be published in the Proceedings of
"International Symposium on Structure of Exotic Nuclei and Nuclear Forces
(SENUF 06)", March 2006, Tokyo, Japa
Ion sources at GANIL
International audienceThe GANIL produces since many years heavy ion beams with Electron Cyclotron Resonance ion sources. Different facilities have been constructed during the last years in order to allow experiments in a large range of energy (from some tens of kV to 100 MeV/nucleon). The list of available ions has been greatly extended with the construction of the SPIRAL1 facility that produces and accelerates radioactives ions . An overview of the different developments made at GANIL for stable and radioactive ion beam production including the sources for the SPIRAL2 project is given in this paper
Release properties of UC and molten U targets
The release properties of UC and molten U thick targets associated with a Nier- Bernas ion source have been studied. Two experimental methods are used to extract the release time. Results are presented and discussed for Kr, Cd, I and Xe
UC target design for the SPIRAL 2 project and the ALTO project
ACC NESTERInternational audienceTwo ways of production of radioactive beams using uranium carbide targets are taken into consideration: fission induced by fast neutrons and by bremsstrahlung radiation. For the SPIRAL 2 project, the fission of 238U in uranium carbide target will be induced by a neutron flow created by bombarding a carbon converter with a 40 MeV high intensity deuteron beam. Calculations and design of the target in order to reach 1013 fissions/s with good release time have been done. The second way is the photofission using an electron beam. In 2005 the ALTO project (Accélérateur Linéaire AuprÚs du Tandem d'Orsay) will give a 50 MeV/10A electron beam. This facility will allow more than 1011 fissions/s. In this case, the electron beam hits the target without converter. Calculations realised in order to estimate the production are used to choose the best target shape. For the two cases some R & D on targets to improve release is described
COMPLIS experiments : COllaboration for spectroscopy Measurements using a Pulsed Laser Ion Source
Laser spectroscopy measurements have been carried out on very neutron-deficient isotopes of Au, Pt and Ir, produced as daughter elements from a Hg ISOLDE beam. For these transitional region nuclides, the hyperfine structure (HFS) and isotope shift (IS) were measured by Resonance Ionization Spectroscopy (RIS). Magnetic moments ÎŒ, spectroscopic quadrupole moments Qs and changes of the nuclear mean square charge radius ÎŽărc 2ăalong isotopic series have been extracted. For some results, a detailed comparison with theoretical predictions is presented. (Springer
Finding Homogeneity in HeterogeneityâA New Approach to Quantifying Landscape Mosaics Developed for the Lao PDR
A key challenge for land change science in general and research on swidden agriculture in particular, is linking land cover information to humanâenvironment interactions over larger spatial areas. In Lao PDR, a country facing rapid and multi-level land change processes, this hinders informed policy- and decision-making. Crucial information on land use types and people involved is still lacking. This article proposes an alternative approach for the description of landscape mosaics. Instead of analyzing local land use combinations, we studied land cover mosaics at a meso-level of spatial scale and interpreted these in terms of humanâenvironmental interactions. These landscape mosaics were then overlaid with population census data. Results showed that swidden agricultural landscapes, involving 17% of the population, dominate 29% of the country, while permanent agricultural landscapes involve 74% of the population in 29% of the territory. Forests still form an important component of these landscape mosaics
Imaging subwavelength holes in chromium films in scanning near-field optical microscopy. Comparison between experiments and calculation
Near-field optical signals are imaged in the vicinity of nano-holes using two different near-field optical microscopes. The experimental results are compared with electromagnetic field calculations based on a modal approximation. It turns out that an optical fibre detects the Poynting vector whereas the apertureless tip is sensitive to the field amplitude
Comparison of nanoparticle diameter measurements by Atomic Force Microscopy and Scanning Electron Microscopy
Using combined AFM ( Atomic Force Microscope) and a SEM (Scanning Electron Microscope) makes it possible to accurately measure a nano-object in 3 dimensions. This paper deals with the traceable measurements of the size and the size distribution of a SiO2 spherical shaped nanoparticle population performed by both microscopy techniques. The complementary nature of AFM and SEM is investigated. The construction of size distribution histogram was carried out by means of a homemade program described here. This semi-automatic program is capable of counting only isolated nanoparticles and eliminating measurement artefacts and aggregates. Finally, a comparison between both measurement types is proposed
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