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Title: Electrostatic ion acceleration across a diverging magnetic field

Abstract

Electrostatic ion acceleration across a diverging magnetic field, which is generated by a solenoid coil, permanent magnets, and a yoke between an upstream ring anode and a downstream off-axis hollow cathode, is investigated. The cathode is set in an almost magnetic-field-free region surrounded by a cusp. Inside the ring anode, an insulating wall is set to form an annular slit through which the working gas is injected along the anode inner surface, so the ionization of the working gas is enhanced there. By supplying 1.0 Aeq of argon as working gas with a discharge voltage of 225 V, the ion beam energy reached about 60% of a discharge voltage. In spite of this unique combination of electrodes and magnetic field, a large electrical potential drop is formed almost in the axial direction, located slightly upstream of the magnetic-field-free region. The ion beam current almost equals the equivalent working gas flow rate. These ion acceleration characteristics are useful for electric propulsion in space.

Authors:
; ; ;  [1]
  1. Department of Aerospace Engineering, Nagoya University, Nagoya, Aichi 464-8603 (Japan)
Publication Date:
OSTI Identifier:
22594404
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACCELERATION; ANODES; ARGON; BEAM CURRENTS; ELECTRIC POTENTIAL; FLOW RATE; GAS FLOW; HOLLOW CATHODES; ION BEAMS; IONIZATION; IONS; MAGNETIC FIELDS; PERMANENT MAGNETS; RINGS; SOLENOIDS; SURFACES

Citation Formats

Ichihara, D., E-mail: ichihara@fuji.nuae.nagoya-u.ac.jp, Uchigashima, A., Iwakawa, A., and Sasoh, A. Electrostatic ion acceleration across a diverging magnetic field. United States: N. p., 2016. Web. doi:10.1063/1.4960363.
Ichihara, D., E-mail: ichihara@fuji.nuae.nagoya-u.ac.jp, Uchigashima, A., Iwakawa, A., & Sasoh, A. Electrostatic ion acceleration across a diverging magnetic field. United States. doi:10.1063/1.4960363.
Ichihara, D., E-mail: ichihara@fuji.nuae.nagoya-u.ac.jp, Uchigashima, A., Iwakawa, A., and Sasoh, A. Mon . "Electrostatic ion acceleration across a diverging magnetic field". United States. doi:10.1063/1.4960363.
@article{osti_22594404,
title = {Electrostatic ion acceleration across a diverging magnetic field},
author = {Ichihara, D., E-mail: ichihara@fuji.nuae.nagoya-u.ac.jp and Uchigashima, A. and Iwakawa, A. and Sasoh, A.},
abstractNote = {Electrostatic ion acceleration across a diverging magnetic field, which is generated by a solenoid coil, permanent magnets, and a yoke between an upstream ring anode and a downstream off-axis hollow cathode, is investigated. The cathode is set in an almost magnetic-field-free region surrounded by a cusp. Inside the ring anode, an insulating wall is set to form an annular slit through which the working gas is injected along the anode inner surface, so the ionization of the working gas is enhanced there. By supplying 1.0 Aeq of argon as working gas with a discharge voltage of 225 V, the ion beam energy reached about 60% of a discharge voltage. In spite of this unique combination of electrodes and magnetic field, a large electrical potential drop is formed almost in the axial direction, located slightly upstream of the magnetic-field-free region. The ion beam current almost equals the equivalent working gas flow rate. These ion acceleration characteristics are useful for electric propulsion in space.},
doi = {10.1063/1.4960363},
journal = {Applied Physics Letters},
number = 5,
volume = 109,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 2016},
month = {Mon Aug 01 00:00:00 EDT 2016}
}
  • The flow structure of ions in a diverging magnetic field has been experimentally studied in an electron cyclotron resonance plasma. The flow velocity field of ions has been measured with directional Langmuir probes calibrated with the laser induced fluorescence spectroscopy. For low ion-temperature plasmas, it is concluded that the ion acceleration due to the axial electric field is important compared with that of gas dynamic effect. It has also been found that the detachment of ion stream line from the magnetic field line takes place when the parameter |f{sub ci}L{sub B}/V{sub i}| becomes order unity, where f{sub ci}, L{sub B},more » and V{sub i} are the ion cyclotron frequency, the characteristic scale length of magnetic field inhomogeneity, and the ion flow velocity, respectively. In the detachment region, a radial electric field is generated in the plasma and the ions move straight with the ExB rotation driven by the radial electric field.« less
  • Heating of an initially cold plasma by a direct magnetosonic wave is treated theoretically.
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