Author: Rácz, R.
Paper Title Page
MODO01 Structural Information on the ECR Plasma by X-ray Imaging 30
 
  • R. Rácz, S. Biri
    ATOMKI, Debrecen, Hungary
  • C. Caliri, G. Castro, S. Gammino, D. Mascali, L. Neri, F.P. Romano
    INFN/LNS, Catania, Italy
  • J. Pálinkás
    DU, Debrecen, Hungary
  • F.P. Romano
    IBAM-CNR, Catania, Italy
 
  Precise knowledge on the density distribution of the Electron Cyclotron Resonance Ion Source plasma is needed by several reasons: i) in order to possibly improve the quality parameters of the extracted ion beam (emittance, brightness) strongly linked to the plasma structure, ii) to correctly investigate the recently observed plasma instabilities and/or the implementation of alternative heating methods (e.g. modal conversion) iii) in order to improve the general microwave-to-plasma coupling efficiency, in view of a microwave-absorption oriented design of future ECRIS. The non-destructive spectroscopic diagnostic methods give information always corresponding to an integration over the whole plasma volume. X-ray imaging by pin-hole camera can partly overcome this limitation. We performed volumetric and space resolved X-ray measurements at the ATOMKI ECRIS operated at lower frequencies than usual. The experimental setup in detail and the methods how the working parameters were selected will be shown. The integrated and photon-counting analyses of the collected plasma images show a strong effect of the frequency and magnetic field on the plasma structure and local energy content.  
slides icon Slides MODO01 [10.710 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-MODO01  
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WEAO03 Practical Comparison of Two-Frequency Heating Phenomena in Different ECR Ion Sources 55
 
  • A. Kitagawa
    NIRS, Chiba-shi, Japan
  • S. Biri, R. Rácz
    ATOMKI, Debrecen, Hungary
  • Y. Kato
    Osaka University, Graduate School of Engineering, Osaka, Japan
  • M. Muramatsu
    National Institute of Radiological Sciences, Chiba, Japan
  • W. Takasugi
    AEC, Chiba, Japan
 
  In order to improve highly-charged ion production from the 18GHz NIRS-HEC ECRIS, our group has studied the mixture of two microwaves of which the frequencies were close together each. Our conclusion was that when an additional microwave is added to the primary microwave, the plasma stability is improved. The output current of the highly charged ion beam was proportional to the total power of both microwaves. The dependence on the additional frequency showed the fine structure. Since this structure depended on the magnetic field, vacuum pressure, and so on, the precise frequency adjustment for maximum output was required under each condition. Our interest is whether the above-mentioned phenomenon can be demonstrated using a different ion source where the two frequencies are even far from each other. We installed a 17.75-18.25 GHz microwave system in addition to the 14.3 GHz klystron amplifier of the ATOMKI ECRIS. Argon output currents at various values of the microwave power and frequency were studied. The dependence on the total power shows the similar tendency as at NIRS. The dependence on the additional frequency also shows the fine structure. Detailed data will be presented.  
slides icon Slides WEAO03 [4.648 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-WEAO03  
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