WECOBK —  Charge Breeding, Optics   (25-Aug-10   11:00—12:30)
Chair: O.K. Kester, NSCL, East Lansing, Michigan, USA
Paper Title Page
WECOBK01 Commissioning of the ECRIS Charge State Breeder at TRIUMF 178
 
  • F. Ames, R.A. Baartman, P.G. Bricault, K. Jayamanna
    TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
  • T. Lamy
    LPSC, Grenoble, France
 
  Radioactive isotopes produced at the ISOL facility ISAC at TRIUMF are usually extracted from the target ion source system as singly charged ions. If the mass of those ions exceeds A=30 their acceleration requires the breeding to highly charged ions. A modified version of an ECRIS charge breeder (14.5 GHz PHOENIX from Pantechnik) has been installed and a first on-line test resulting in the successful acceleration of 80Rb14+ has been performed already in 2008. During the radioactive beam time periods of 2009 and 2010 further measurements with stable and radioactive ions from different target ion source combinations have been performed to fully commission the system. Breeding efficiencies of several percent in the maximum of the charge state distribution have been achieved. Detailed results will be presented.  
slides icon Slides WECOBK01 [1.230 MB]  
 
WECOBK02 Recent Performance of the ANL ECR Charge Breeder 181
 
  • R.C. Vondrasek, A. Kolomiets, R.C. Pardo, R.H. Scott
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
The construction of the Californium Rare Ion Breeder Upgrade (CARIBU), a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS), is nearing completion. The facility will use fission fragments, with charge 1+ or 2+, from a 1 Ci 252Cf source; thermalized and collected into a low-energy particle beam by a helium gas catcher. An existing ATLAS ECR ion source was modified to function as a charge breeder in order to raise the ion charge sufficiently for acceleration in the ATLAS linac. A surface ionization source or an RF discharge source provide beams for charge breeding studies. An achieved efficiency of 11.9% for 85Rb19+, with a breeding time of 200 msec, and 15.6% for 84Kr17+ has been realized. Both results are with the source operating with two RF frequencies (10.44 + 11.90 GHz). After modification to the injection side iron plug, the charge breeder has been operated at 50 kV, a necessary condition for the resolution of the isobar separator.
 
slides icon Slides WECOBK02 [3.351 MB]  
 
WECOBK03 Fine Frequency Tuning of the PHOENIX Charge Breeder Used as a Probe for ECRIS Plasmas 184
 
  • T. Lamy, J. Angot, M. Marie-Jeanne, J. Médard, P. Sortais, T. Thuillier
    LPSC, Grenoble Cedex, France
  • A. Galatà
    INFN/LNL, Legnaro (PD), Italy
  • H. A. Koivisto, O.A. Tarvainen
    JYFL, Jyväskylä, Finland
 
  Fine frequency tuning of ECR ion sources is a main issue to optimize the production of multiply charged ion beams. The PHOENIX charge breeder operation has been tested in the range 13,75 - 14,5 GHz with an HF power of about 400 W. The effect of this tuning is analyzed by measuring the multi-ionization efficiency obtained for various characterized injected 1+ ion beams (produced by the 2.45 GHz COMIC source). The 1+/n+ method includes the capture and the multi ionization processes of the 1+ beam and may be considered as a plasma probe. The n+ spectra obtained could be considered, in first approach, as an image of the plasma of the charge breeder. However, in certain conditions it has been observed that the injection of a few hundreds of nA of 1+ ions (i.e.: Xe1+) in the plasma of the charge breeder, is able to destroy the charge state distribution of the support gas (i.e.: up to 40 % of O6+ and O7+ disappears). The study of this phenomenon will be presented along with plasma potential measurements for various charge states. This study may help to understand the ECRIS creation (or destruction) of highly charged ions.  
slides icon Slides WECOBK03 [7.745 MB]  
 
WECOBK04 Preliminary Results of Spatially Resolved ECR Ion Beam Profile Investigations 188
 
  • L. Panitzsch, M. Stalder, R.F. Wimmer-Schweingruber
    IEAP, Kiel, Germany
 
  The Department of Experimental and Applied Physics (IEAP) at the University of Kiel (CAU Kiel) is establishing a solar wind laboratory for the calibration of space instrumentation. The main item of this facility is a 11GHz (Plateau) ECR ion source. It can be operated at two different radial magnetic confinements, using a set of permanent magnets in either hexapole or dodekapole arrangement. While beam focussing by moving the extraction along the beam line to match the ion beam into the analysing magnet is well known, little is known about beam steering by moving the extraction in the plane perpendicular to the beam line. For the hexapole-configuration we will present our results about the feasibility of ion beam focussing and steering using a 3D-movable extraction. The beam profiles of these measurements will be recorded in comparatively high resolution with a Faraday cup array (see paper doi: 10.|10|63/1.3246787). This method will be shortly introduced within this talk, as well.  
slides icon Slides WECOBK04 [13.317 MB]