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Title: Gas breakdown in electron cyclotron resonance ion sources

Abstract

The realization of the beta-beam project (http://beta-beam.web.cern.ch/beta-beam/) assumes the formation of a pulsed ion beam of helium and neon radioactive isotopes. A pulsed electron cyclotron resonance (ECR) source of multicharged ions has been proposed to produce such a beam [P. Sortais et al., Rev. Sci. Instrum. 75, 1610 (2004)]. The rising of plasma density up to a stationary level must be fast enough to actualize this approach. This condition is mandatory to avoid particle losses in the transmission line. In the presented work, the rising time of the plasma density in an ECR ion source from a background level up to 98% of a stationary level is calculated. A zero-dimensional model of plasma formation in a mirror trap [V. Semenov et al., Rev. Sci. Instrum. 73, 635 (2002)] is used, able to make calculation for a wide range of microwave frequencies. Plasma confinement regime can either be classic (Pastoukhov [Rev. Plasma Phys. 13, 203 (1987)]) or gas dynamic, depending on the plasma parameters. The calculations are in good agreement with the experimental results obtained at the SMIS'37 setup. Numerical calculations also show that particle losses can be significantly reduced by pumping effect; thanks to microwave frequency increase above 40 GHz.

Authors:
; ; ; ; ; ;  [1];  [2]
  1. Institute of Applied Physics of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation)
  2. (France)
Publication Date:
OSTI Identifier:
20778965
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 77; Journal Issue: 3; Conference: 11. international conference on ion sources, Caen (France), 12-16 Sep 2005; Other Information: DOI: 10.1063/1.2166671; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ECR ION SOURCES; ELECTRON CYCLOTRON-RESONANCE; GHZ RANGE 01-100; HELIUM; HIGH-FREQUENCY DISCHARGES; MAGNETIC MIRRORS; MULTICHARGED IONS; NEON; PARTICLE LOSSES; PLASMA; PLASMA CONFINEMENT; PLASMA DENSITY; RADIOACTIVE ION BEAMS; RADIOISOTOPES

Citation Formats

Skalyga, V.A., Zorin, V.G., Izotov, I.V., Sidorov, A.V., Lamy, T., Sortais, P., Thuillier, T., and Laboratoire de Physique Subatomique et de Cosmologie UJF-IN2P3-CNRS, 53 Avenida Des Martyrs, 38026 Grenoble Cedex. Gas breakdown in electron cyclotron resonance ion sources. United States: N. p., 2006. Web. doi:10.1063/1.2166671.
Skalyga, V.A., Zorin, V.G., Izotov, I.V., Sidorov, A.V., Lamy, T., Sortais, P., Thuillier, T., & Laboratoire de Physique Subatomique et de Cosmologie UJF-IN2P3-CNRS, 53 Avenida Des Martyrs, 38026 Grenoble Cedex. Gas breakdown in electron cyclotron resonance ion sources. United States. doi:10.1063/1.2166671.
Skalyga, V.A., Zorin, V.G., Izotov, I.V., Sidorov, A.V., Lamy, T., Sortais, P., Thuillier, T., and Laboratoire de Physique Subatomique et de Cosmologie UJF-IN2P3-CNRS, 53 Avenida Des Martyrs, 38026 Grenoble Cedex. Wed . "Gas breakdown in electron cyclotron resonance ion sources". United States. doi:10.1063/1.2166671.
@article{osti_20778965,
title = {Gas breakdown in electron cyclotron resonance ion sources},
author = {Skalyga, V.A. and Zorin, V.G. and Izotov, I.V. and Sidorov, A.V. and Lamy, T. and Sortais, P. and Thuillier, T. and Laboratoire de Physique Subatomique et de Cosmologie UJF-IN2P3-CNRS, 53 Avenida Des Martyrs, 38026 Grenoble Cedex},
abstractNote = {The realization of the beta-beam project (http://beta-beam.web.cern.ch/beta-beam/) assumes the formation of a pulsed ion beam of helium and neon radioactive isotopes. A pulsed electron cyclotron resonance (ECR) source of multicharged ions has been proposed to produce such a beam [P. Sortais et al., Rev. Sci. Instrum. 75, 1610 (2004)]. The rising of plasma density up to a stationary level must be fast enough to actualize this approach. This condition is mandatory to avoid particle losses in the transmission line. In the presented work, the rising time of the plasma density in an ECR ion source from a background level up to 98% of a stationary level is calculated. A zero-dimensional model of plasma formation in a mirror trap [V. Semenov et al., Rev. Sci. Instrum. 73, 635 (2002)] is used, able to make calculation for a wide range of microwave frequencies. Plasma confinement regime can either be classic (Pastoukhov [Rev. Plasma Phys. 13, 203 (1987)]) or gas dynamic, depending on the plasma parameters. The calculations are in good agreement with the experimental results obtained at the SMIS'37 setup. Numerical calculations also show that particle losses can be significantly reduced by pumping effect; thanks to microwave frequency increase above 40 GHz.},
doi = {10.1063/1.2166671},
journal = {Review of Scientific Instruments},
number = 3,
volume = 77,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • The major infrastructures of nuclear physics in Europe adopted the technology of electron cyclotron resonance (ECR) ion sources for the production of heavy-ion beams. Most of them use 14 GHz electron cyclotron resonance ion sources (ECRISs), except at INFN-LNS, where an 18 GHz superconducting ECRIS is in operation. In the past five years it was demonstrated, in the frame of the EU-FP5 RTD project called ''Innovative ECRIS,'' that further enhancement of the performances requires a higher frequency (28 GHz and above) and a higher magnetic field (above 2.2 T) for the hexapolar field. Within the EU-FP6 a joint research activitymore » named ISIBHI has been established to build by 2008 two different ion sources, the A-PHOENIX source at LPSC Grenoble, reported in another contribution, and the multipurpose superconducting ECRIS (MS-ECRIS), based on fully superconducting magnets, able to operate in High B mode at a frequency of 28 GHz or higher. Such a development represents a significant step compared to existing devices, and an increase of typically a factor of 10 for the intensity is expected (e.g., 1 emA for medium charge states of heavy ions, or hundreds of e{mu}A of fully stripped light ions, or even 1 e{mu}A of charge states above 50{sup +} for the heaviest species). The challenging issue is the very high level of magnetic field, never achieved by a minimum B trap magnet system; the maximum magnetic field of MS-ECRIS will be higher than 4 or 5 T for the axial field and close to 2.7 T for the hexapolar field. The detailed description of the MS-ECRIS project and of its major constraints will be given along with the general issues of the developments under way.« less
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  • The 14 GHz Electron Cyclotron Resonance Ion Source at University of Jyvaeskylae, Department of Physics (JYFL) has been operated in pulsed mode in order to study the plasma breakdown and preglow effect. It was observed that the plasma breakdown time and preglow characteristics are affected by seed electrons provided by a continuous low power microwave signal at secondary frequency. Sustaining low density plasma during the off-period of high power microwave pulses at the primary frequency shifts the charge state distribution of the preglow transient toward higher charge states. This could be exploited for applications requiring fast and efficient ionization ofmore » radioactive elements as proposed for the Beta Beam project within the EURISOL design study, for example. In this article we present results measured with helium and neon.« less
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