The first AGATA triplet of highly segmented germanium detectors, on a test bench.
The atomic nucleus is a many-body quantum system of strongly interacting particles, the protons and neutrons. As a complete description of this system from first principles is not possible, mean-field and shell models are used to describe the nuclear structure. Advances come from a constant interplay between nuclear structure theory and experiments that test the models under extreme conditions, such as extreme ratios between protons and neutrons, extreme mass, spin, or deformation. The nuclear physicists of Dapnia use radioactive beams delivered by the SPIRAL facility at GANIL to study exotic nuclei under extreme conditions and thereby test the validity and limitations of the nuclear models. These studies are complemented by experiments at other facilities like the Legnaro National Laboratory (
last update : 10-18 00:00:00-2005 (609)
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15-02-2010
The CHyMENE project (Cible d'Hydrogène Mince pour l'Etude des Noyaux Exotiques -Thin hydrogen target for the study of exotic nuclei) has the ambitious goal of producing a thin target of pure hydrogen, without using a container, suitable for experiments using the low-energy heavy ion beam planned for SPIRAL2.
A team from IRFU (SPhN and SACM) and from l'Inac/SBT have recently applied cryogenic techniques to successfully produce a ribbon of solid hydrogen 100 μm thick. The target will soon be tested in the beam. This will be a world first.
Below: Interview with Alain GILLIBERT, who is working on the CHyMENE project with Alexandre OBERTELLI and ... More » |
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07-10-2010
The instrument known as MUSETT1 detected its first heavy nuclei during a commissioning experiment that took place in early April 2010 at the GANIL2 accelerator in Caen. MUSETT was built for identifying very heavy elements: transfermium, which are the elements beyond fermium (Z=100). Nuclear physicists are interested in these extreme state of matter for testing the theoretical models that describe the nuclei. Initial results obtained with MUSETT are highly satisfactory, providing very good identification of the produced isotopes, thanks to an original method called ‘genetic correlations’. This method can tag nuclei by detecting its decay. MUSETT provides a ... More » |
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14-12-2010
At a meeting in Brussels of the NUPECC Committee(1) on December 9, the researchers presented their long term plan for maintaining the leading position currently enjoyed by European institutions in the field of nuclear physics. The Spiral2 project in Caen, a collaboration between the CNRS/IN2P3(2) and the CEA/DSM(3), is one of the projects already contributing to this European strategy.
The long term plan for nuclear physics may be found on the NUPECC site in a number of forms, including the full 200 page report, a 20 page summary and a 20 minute video.
http://www.nupecc.org/index.php?display=lrp2010/main
Contact:
Philippe CHOMAZ, chef de ... More » |
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10-12-2008
The high energy part of the SPIRAL2 linear accelerator (new GANIL1 accelerator scheduled for implementation in 2012) uses two types of superconducting cavities. IRFU's Accelerator, Cryogenics and Magnetism Department is responsible for the design and development of 12 cryomodules2 of the first type, to be installed at the injector output. On December 8, 2008, the qualification prototype cryomodule was successfully tested at full power. The superconducting cavity attained an accelerating gradient of 10.3 MV/m (million volts per meter), far greater than the specified value of 6.5 MV/m. |
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18-06-2008
The shape of an atomic nucleus reflects the shell structure of the protons and neutrons of which it is formed. If the shells are completely filled, we speak of a "magic" nucleus, which is spherical in shape. Most nuclei, however, tend to be deformed because their shells are only partially filled. The most commonly encountered shapes are elongated (prolate) or flattened (oblate); these shapes can change from on nucleus to its neighbour by adding or removing a proton or neutron. In some cases it is sufficient to rearrange the protons or neutrons within the same nucleus to change its shape. The same nucleus can therefore assume different shapes corresponding to states of ... More » |
Experiments
