HITRAP: A facility at GSI for highly charged ions

An overview and status report of the new trapping facility for highly charged ions at the Gesellschaft fuer Schwerionenforschung is presented. The construction of this facility started in 2005 and is expected to be completed in 2008. Once operational, highly charged ions will be loaded from the experimental storage ring ESR into the HITRAP facility, where they are decelerated and cooled. The kinetic energy of the initially fast ions is reduced by more than fourteen orders of magnitude and their thermal energy is cooled to cryogenic temperatures. The cold ions are then delivered to a broad range of atomic physics experiments.Comment: 8 pages, 11 figure

State selective x ray studies of radiative recombination into bare and H like uranium at threshold energies

A state selective investigation of radiative recombination RR at threshold energies has been performed by x ray detection at the electron cooler of the ESR storage ring at GSI for decelerated bare and hydrogen like uranium ions. The application of the deceleration mode enabled us to observe state selective RR into the K and L shell of bare and H like uranium. The observed relative RR intensities into these low laying bound states exhibit a good agreement with rigorous relativistic predictions, whereas the nonrelativistic approach fails to reproduce the data. Furthermore, the scaled relativistic one electron treatment seems to be insufficient for the state selective description of RR into H like species at extremely low energies, suggesting the importance of electron electron interactions for the RR process at the threshold

Reduction of uncertainties in exposure assessment based on environmental monitoring data.

Emergency preparedness and response systems for nuclear and radiological emergencies have to deal with decision-making in situations with relevant uncertainties. Consistent and appropriate protective measures must be decided before, during and after emergency situations. CONFIDENCE WP2 research helps to improve this decision-making process in the urgent response and the early response phase of emergency situations with potential major releases to atmosphere. This paper describes methods to reduce uncertainties in dose assessment for the population using data from stationary and mobile environmental monitoring programs. A special focus is given to identification of the measurement uncertainties of stationary and mobile monitoring systems. Methods to reduce these uncertainties and procedures to optimise mobile monitoring strategies are discussed. A first contribution towards assessing the quality of dose-rate measurements performed by the general population is made. In addition, the paper introduces approaches for advanced dose assessment tools using monitoring data and concepts for identifying critically exposed groups

Polarization Measurements of Radiative Electron Capture Transitions in Highly Charged Ions

International audienceA dedicated Si(Li) Compton polarimeter combining energy and time resolution with a large detection area of 64x64 mm(2) and a two dimensional position resolution of 2 mm has been used for the first time to study the polarization of x-rays emitted via radiative electron capture (REC) into the K and L-shell of heavy highly charged ions. First data for the collision system 96.6 MeV/u U(92+) -> H(2) are presented. The angular distribution of the Compton scattered photons inside the detector indicates that both K- and L-REC processes lead to the emission of strongly linearly polarized light

First observation of bound-state #beta#-decay

SIGLEAvailable from TIB Hannover: RO 801(92-45) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Isotope Shifts in Dielectronic Recombination:From Stable to In-flight-Produced Nuclei

The study of isotope shifts and hyperfine effects in dielectronic recombination (DR) resonance spectra strikes a conceptually new path for investigations of nuclear properties such as charge radius, spin, magnetic moment of nuclei or lifetimes of long-lived excited nuclear states. A series of DR experiments with heavy three-electron ions (Li-like) was performed at the heavy-ion storage ring ESR of the GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany. In a pilot experiment the two stable isotopes A=142 and A=150 of neodymium ANd57+ were investigated. From the displacement of DR resonances the isotope shifts δE142,150(2s – 2Pl/2) = 40.2(3)(6) meV and δE142,150(2s – 2p3/2) = 42.3(12)(20) meV for 2s – 2Pj transitions of the Li-like ions have been obtained. An evaluation within a full QED framework yielded a change in the mean-square charge radius of 142,150δ(r2) = −1.36(1)(3) fm2. At GSI, in addition to stable isotopes, in-flight synthesized radioisotopes can be studied as well. The production of radioisotopes of interest, the subsequent separation in the storage ring ESR and first DR experiments with the exotic nuclei 237U89+ and 234Pa88+ (Z=91) are presented. The paper is concluded with a brief outlook at future DR experiments with heavy radioisotopes at the ESR