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Résumé du preprint DAPNIA-02-63

DAPNIA-02-63
First plasma analysis of the CEA/Saclay ECR hydrogen negative ion source.
R. Gobin, P-Y. Beauvais, K. Benmeziane, O. Delferrière, R. Ferdinand, F. Harrault, J-M. Lagniel, J. Sherman(1), Commissariat à l'Energie Atomique, CEA-Saclay, DSM/DAPNIA/SEA 91191 Gif sur Yvette Cedex, France (1) Permanent address: Los Alamos National Laboratory, Los Alamos, N.M. 87 545, USA
Reliable high-intensity H- ion source development is now part of the CEA/Saclay work in the field of high-intensity linear accelerators. A 2.45 GHz ECR H- ion source and test bench have been built. This new source has been designed taking into account our experience on the French high intensity ECR proton source. For H- ion production, the high-energy electrons created in the ECR zone are trapped by a dipole magnetic filter. A rectangular 210 mm long plasma chamber and an intermediate iron shield are used to minimize the magnetic field in the extraction region. A second magnetic dipole separates electrons and negative ions in a 10 kV extraction system. To reduce the electron/H- ratio, the plasma electrode is biased by a power supply. The first helium plasma allowed us to verify the satisfactory electron separator behavior. Pulsed hydrogen plasma is currently produced. The first plasma characterization is under progress as a function of ion source parameters by using Langmuir probes and optical spectrometer. The first results are presented and possible evolutions toward a higher efficiency source will be discussed.

DAPNIA-02-63

First plasma analysis of the CEA/Saclay ECR hydrogen negative ion source.

R. Gobin, P-Y. Beauvais, K. Benmeziane, O. Delferrière, R. Ferdinand, F. Harrault, J-M. Lagniel, J. Sherman(1), Commissariat à l'Energie Atomique, CEA-Saclay, DSM/DAPNIA/SEA 91191 Gif sur Yvette Cedex, France (1) Permanent address: Los Alamos National Laboratory, Los Alamos, N.M. 87 545, USA

Reliable high-intensity H- ion source development is now part of the CEA/Saclay work in the field of high-intensity linear accelerators. A 2.45 GHz ECR H- ion source and test bench have been built. This new source has been designed taking into account our experience on the French high intensity ECR proton source. For H- ion production, the high-energy electrons created in the ECR zone are trapped by a dipole magnetic filter. A rectangular 210 mm long plasma chamber and an intermediate iron shield are used to minimize the magnetic field in the extraction region. A second magnetic dipole separates electrons and negative ions in a 10 kV extraction system. To reduce the electron/H- ratio, the plasma electrode is biased by a power supply. The first helium plasma allowed us to verify the satisfactory electron separator behavior. Pulsed hydrogen plasma is currently produced. The first plasma characterization is under progress as a function of ion source parameters by using Langmuir probes and optical spectrometer. The first results are presented and possible evolutions toward a higher efficiency source will be discussed.