Can Collaboration Engineering help Open Source Communities to structure their activities?

Collaborative work became an importantstake for productivity, performance andinnovation for companies. They bet more andmore on communities of practice to supportcollaboration, sharing and creation of knowledge.The goal of this paper is to analyze the possiblecontribution of the Collaboration Engineering inthe working of these communities, by taking asexample, the Open Source communities.Collaboration Engineering, communities of practice,collaboration, Open Source communities.

Review of ion-source developments for radioactive ion-beam facilities

The ion-sources dedicated to the production of radioactive ion beams (RIB) shall be highly efficient, selective and fast. This efficiency is mandatory since only limited amounts of radionuclides are produced. Chemical selectivity is needed to confine other elements near to the production site and to suppress isobaric contaminants. Eventually, the ion-source shall only decay the radioisotopes by a fraction of their half-life to reduce decay losses. The world wide spread RIB facilities came up with a large variety of solutions to meet part or all of these requirements such as: ion traps, surface, plasma, sputtering, electron cyclotron resonance and laser ion- sources. In this review, the latest developments are presented and their applications to charge states breeder systems proposed for post-acceleration are discussed. (59 refs)

Exotic ion-beams targets and sources

Exotic beams of short-lived radioisotopes are produced in nuclear reactions such as thermal neutron induced fission, target or projectile fragmentation and fusion reactions. For a given radioactive ion beams (RIB), different production mode are in competition. For each of them the cross section, the intensity of the projectile beam and the target thickness define an upper production rate. The final yield relies on the optimisation of the ion-source, which shall be fast and highly efficient in view of the limited production cross section and on minimum diffusion time out of the target matrix or fragment catcher to reduce decay losses. Eventually, either chemical or isobaric selectivity is needed to confine unwanted elements near to the production site. These constraints are discussed for pulsed or dc driven RIB facilities and the solutions to some of the technical challenges will be illustrated by examples of actually scarcely produced near drip line elements

Luis Noussan-Lettry : curriculum

Fil: Noussan-Lettry, Luis. Universidad Nacional de Cuyo. Facultad de Filosofía y Letra

Sobre maestros, milicia y taxonomía

Fil: Noussan-Lettry, Luis. Universidad Nacional de Cuyo. Facultad de Filosofía y Letra

Development of High Efficiency Versatile Arc Discharge Ion Source (VADIS) at CERN Isolde

We report here recent developments of Forced Electron Beam Impact Arc Discharge (FEBIAD) ion sources at CERN-ISOLDE. As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5 to 20 times larger than with the standard ISOLDE FEBIAD ion sources, and reach 60% for Radon, which allowed the identification at ISOLDE of 229Rn, an isotope that had never previously been observed in the laboratory. A factor 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model which gives precise insights on the processes affecting the ionization is used to design optimal sources for the different chemical classes of the produced isotopes, as already demonstrated for noble gases

Transverse emittance investigation of the ISOLDE target ion sources

In order to produce target-ion sources allowing for a high isotopic resolution in the separator, CERN/ISOLDE (Isotope Separator On Line) has purchased a commercial emittance metre, capable of measuring transverse phase-space emittances for ion-beam intensities down to approximately 1 nA. It was installed at the ISOLDE off-line separator where targets are tested with respect to material purity and the ion-source efficiencies are determined. Now, also the emittance and brightness are measured for different stable elements. An extensive programme has been launched aiming at a complete survey of the emittance dependence on the various ion-source parameters. Results from the measurements on the different ISOLDE ion-source types, with associated analysis, are presented