Charge Breeding

Paper Title Page
MOPO-22 Wall Distribution of Ions Externally Injected for Charge-Breeding in ECRIS 120
 
  • M. Oyaizu, S. Arai, M. Okada
    KEK, Ibaraki
  • Y. Fuchi, Y. Hirayama, N. Imai, H. Ishiyama, S. C. Jeong, H. Miyatake, Y. Watanabe
    KEK, Tokai Branch, Tokai, Naka, Ibaraki
  • S. Ichikawa, H. Kabumoto, M. Matsuda, A. Osa, Y. Otokawa
    JAEA, Ibaraki-ken
  
  We have successfully converted the singly charged ions of short-lived radioactive nuclei as well as of stable nuclei into the multi-charged ions with the charge-to-mass ratio of about 1/7, by employing KEKCB, an 18GHz ECR charge breeder at TRIAC (Tokai Radioactive Ions Accelerator Complex). However, we observed large difference in charge breeding between gaseous and non-gaseous ion species, i.e. in the injection optics and the resultant charge breeding efficiencies. In order to understand the difference, we investigated how the ions, externally injected to the ECR plasma of KEKCB for breeding their charge states but failed to be re-extracted, were distributed on the wall (surface) of the plasma chamber. To investigate the distribution, we had injected and charge-bred radioactive singly-charged 111In ions with a half-life of 2.9 days. After the operation, we extracted the distribution of the 111In by measuring the residual activity on the wall of the chamber. We have observed an azimuthally asymmetric distribution around the Bmin of axial field configuration on the top of rather symmetric and isotropic distribution, which will be discussed in detail at the workshop.  
poster icon Poster  
TUCO-C04 Far-Tech's ECR Charge Breeder Optimization Simulation Toolset - MCBC, GEM, and IonEx 156
 
  • J. S. Kim, I. N. Bogatu, B. Cluggish, S. Galkin, L. Grubert, L. Zhao
    Far-Tech, Inc., San Diego, California
  
  Funding: This work is supported by the US DOE SBIR program.

FAR-TECH has been developing ECR charge breeder optimization toolset. It consists of three computational modules: [1] the GEM (General ECRIS Model) code, [2] the MCBC (Monte Carlo Beam Capture) code, and [3] the IonEx (Ion extraction) code. The GEM code simulates ECR plasmas via Fokker-Plank electrons and ion fluids. MCBC is a particle tracking code to trace the injected charge breeder beam ions, and IonEx simulates the ion extraction region accurately by resolving the plasma sheaths at the extraction region. Current status of the work will be presented along with examples.

[1] J. S. Kim, L. Zhao, B. P. Cluggish, I. N. Bogatu, and R. Pardo, 'Electron cyclotron resonance charge breeder ion source simulation by MCBC', Rev. Sci. Instrum. 79, 02B906 (2008) [2] D. H. Edgell, J. S. Kim, S. K. Wong, R. C. Pardo and R. C. Vondrasek, Rev. Sci. Instrum. 71, 666 (2000) [3] B. P. Cluggish, S. A. Galkin, and J. S. Kim, 'Modeling Ion Extraction from an ECR Ion Source', Proceeding of the 2007 Particle Accelerator Conference, Albuquerque, NM, June 25-29, 2007

 
slides icon Slides  
WECO-A01 New Configuration and Results with the LPSC Charge Breeder 180
 
  • T. Lamy, J. Angot, C. Fourel, T. Thuillier
    LPSC, Grenoble
  
  Funding: This work is supported by EU within the EURONS network under Contract No. RII3-506065.

A 1+ surface ionisation source has been used to produce Sodium and Rubidium beams in order to compare the PHOENIX Booster capture efficiency for different ion masses but with the same beam optics. Yields of 1.9% for 23Na6+ and 3.5% for 85Rb15+, with charge breeding times of 8,6ms/q and 4,6ms/q respectively have been measured. 1+ and n+ emittance measurements are presented along with the capture sensitivity to different parameters (DeltaV plots). Technical modifications have been performed to the charge breeder : replacement of the plasma chamber to allow a double frequency operating (14 + 18 GHz), modification of the injection magnetic plug to reinforce the axial magnetic field and correct its dissymmetry in the 1+ beam deceleration zone, insulation improvement to allow 60kV operation for the SPIRAL2 project. First charge breeding experimental results at 14 and 18GHz in the new configuration are presented and discussed for Rb beams

 
slides icon Slides  
WECO-A02 Status of the ECRIS Charge State Breeding Project at TRIUMF 183
 
  • F. Ames, R. A. Baartman, P. G. Bricault, K. Jayamanna, M. McDonald, P. Schmor
    TRIUMF, Vancouver
  • T. Lamy
    LPSC, Grenoble
  
  Efficient and fast charge state breeding is an important parameter for the acceleration of radioactive ions at ISOL facilities. Most on-line ion sources produce only singly charged ions but efficient accelerators require high charge states. Tests of an ECRIS as charge breeder (14 GHz PHOENIX from Pantechnik) have been performed on a test bench at TRIUMF mainly focussing on the optimization of the efficiency and breeding time. After this the source has been moved on-line to the ISAC facility. Mass separated beams of radioactive ions from the on-line ion sources can be directed into the source as well as ions from a Cs test ion source. The latter will be used for commissioning the system and setting up and optimizing the performance of the source as well as the transport of the highly charged ions to the accelerator. A summary of the results obtained at the test bench and first results from the on line commissioning will be presented.  
slides icon Slides  
WECO-A03 Initial Results of the ECR Charge Breeder for the 252Cf Fission Source Project (CARIBU) at ATLAS 184
 
  • R. C. Vondrasek, J. R. Carr, R. C. Pardo, R. H. Scott
    ANL, Argonne, Illinois
  
  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 in progress. The facility will use fission fragments from a 1 Ci 252Cf source; thermalized and collected into a low-energy particle beam by a helium gas catcher. In order to reaccelerate these beams, the existing ATLAS ECR1 ion source has been redesigned to function as a charge breeder source. An additional high voltage platform has been constructed to accommodate a low charge state stable beam source for charge breeding development work. The design features and initial results of this charge breeder configuration will be discussed.

 
slides icon Slides  
WECO-B01 Design of a Charge-Breeder Ion Source for Texas A&M University 185
 
  • W. D. Cornelius
    SAIC, San Diego, California
  
  Funding: This material is based upon work supported by the U. S. Department of Energy under Award Number DE-FG02-04ER84066.

Scientific Solutions designed and fabricated a 14.5 GHz charge-breeder ECR source for the Texas A&M University Cyclotron facility. This charge-breeder source was designed as a charge-breeder from the start rather than as a conversion of an existing ECR system. In addition, the overall system was designed to be modular so that various components can be easily substituted to facilitate technology developments. This paper details the overall design, the design constraints, and reviews specific performance requirements that resulted in this particular system design.

*Current address: SAIC, 10740 Thornmint Road, San Diego, CA 92127

 
slides icon Slides