182 research outputs found
Ion source developments for stable and radioactive ion beams at GANIL
Since now many years, the Ganil ion source team has in charge to develop ion sources with three main purposes. The first one concerns the radioactive ion production that implies high efficiency ion sources as the amount of created exotic atoms is very low (between 10 to 108 particle per second). The second one deals with high intensities of stable metallic ion beams for the injectors of the accelerator while the last one tries to increase the intensities of very high charge state ion beams for atomic physic. Concerning radioactive ion production, the recent results obtained, in collaboration with the ISN Grenoble group, with the 1+/n+ method drove us to develop a new concept of ecr ion source for monocharged ion production. The results of the first tests of this source will be given. This new idea for the construction of ecr ion source can be applied to multicharged ion production. Concerning the high charge state ion beam production, a new source called SUPERSHYPIE has been built that allow to increase by a factor 2 the length of the plasma of an ECR4M source. This new concept has just been started and has produced arround 50 nAe of Ar17+ . The first results of this new source will be presented. Concerning the developments of metallic ion beams, a separated poster will be presented at this workshop
ECR Ion sources for radioactive ion beam production
17th workshop on ECR Ion Sources and their Applications, Lanzhou, Chine (2006)International audienceECRIS's dedicated to radioactive ion producton must be as efficient as those used for production of stable elements, but in addition they are subject to more specific constraints such as radiation hardness, short atom-to-ion transformation time, beam purity and low cost. Up to now, different target/ion-source system (TISSs) have been designed, using singly-charged ECRISs, multi-charged ion sources or an association of singly-to-multi-charged ECRISs. The main goal, constraints and advantages of different existing ECR setups wil be compared before a more detailed description is given of the one designed for the SPIRAL II project and ist future improvements
Permanent magnets under irradiation and radiocative alkali ion beam development for SPIRAL1
International audienceUp to now, eighteen Target Ion Source Systems (TISSs) have been built and used for the production of radioactive ion beams on SPIRAL 1 facility, based on the Isotope- Separator-On-Line (ISOL) method. The TISSs are composed of thick carbon targets and of fully permanentmagnet Electron Cyclotron Resonance Ion Sources (ECRISs) of the Nanogan III type. After irradiation and a decay period of two years, the irradiated TISSs are dismounted and if their magnetic fields are still suitable, the ECRIS are used with a new target. Thereby thirty-two runs have been performed using new or renewed TISSs. , After irradiation, the measured magnetic field sometimes reveals magnet damage. Our experience is reported here. In the second section, we present the progress on the NanoNaKE setup, which aims to extend the radioactive ion beams in SPIRAL 1 to the alkali elements, by connecting a surface-ionization source to the Nanogan III ECRIS via a compact 1+ ion beam line. The main issues and difficulties are discussed and the preliminary solutions are described
Production of multi-charged phosphorus ions with ecris 'SUPERSHyPIE' at GANIL
The Ganil's Ion Production Group tested the source SUPERSHyPIE123 for theproduction of phosphorus n+ ion beams. The SUPERSHyPIE ecris is used for many testsof multi-charged ion production and supply ion beams for LIMBE4 (low energie beamline). This ion source works with a 14.5ghz RF power injected by a circular waveguide inthe axis of the sourc
Recycling effect of germanium on ECR ion source
After running for three weeks with a 76Ge beam provided by the ECR-4 ion source at GANILwe have investigated the recycling effect of an SF6 plasma. The initial beam was produced bythe classical method, using germanium dioxide in our micro-oven and helium as support gas.The overall ionization efficiency was measured and found to be around 3%. Without theoven, and using SF6 instead of helium, the ECR-4 ion source has been able to produce a verystable beam during a two-week period. The intensity of 76Ge13+ (enrichment 88%) wasincreased to 40 eÎĽA, and the overall ionization efficiency reached 40%.The oven method of production, the recycling effect and perspectives are described in thispaper
Nuclear charge radius of He
The root-mean-square (rms) nuclear charge radius of ^8He, the most
neutron-rich of all particle-stable nuclei, has been determined for the first
time to be 1.93(3) fm. In addition, the rms charge radius of ^6He was measured
to be 2.068(11) fm, in excellent agreement with a previous result. The
significant reduction in charge radius from ^6He to ^8He is an indication of
the change in the correlations of the excess neutrons and is consistent with
the ^8He neutron halo structure. The experiment was based on laser spectroscopy
of individual helium atoms cooled and confined in a magneto-optical trap.
Charge radii were extracted from the measured isotope shifts with the help of
precision atomic theory calculations
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
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 Auprès 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
In gas laser ionization and spectroscopy experiments at the Superconducting Separator Spectrometer (S3): Conceptual studies and preliminary design
International audienceThe results of preparatory experiments and the preliminary designs of a new in-gas laser ionization and spectroscopy setup, to be coupled to the Super Separator Spectrometer S3 of SPIRAL2-GANIL, are reported. Special attention is given to the development and tests to carry out a full implementation of the in-gas jet laser spectroscopy technique. Application of this novel technique to radioactive species will allow highsensitivity and enhanced-resolution laser spectroscopy studies of ground- and excited-state properties of exotic nuclei
Precision Measurement of the First Ionization Potential of Nobelium
One of the most important atomic properties governing an element’s chemical behavior is the energy required to remove its least-bound electron, referred to as the first ionization potential. For the heaviest elements, this fundamental quantity is strongly influenced by relativistic effects which lead to unique chemical properties. Laser spectroscopy on an atom-at-a-time scale was developed and applied to probe the optical spectrum of neutral nobelium near the ionization threshold. The first ionization potential of nobelium is determined here with a very high precision from the convergence of measured Rydberg series to be 6.626   21 ± 0.000   05     eV . This work provides a stringent benchmark for state-of-the-art many-body atomic modeling that considers relativistic and quantum electrodynamic effects and paves the way for high-precision measurements of atomic properties of elements only available from heavy-ion accelerator facilities
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