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Title: Electrostatic acceleration of helicon plasma using a cusped magnetic field

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4900423· OSTI ID:22391983
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  1. Department of Aerospace Engineering, Nagoya University, Nagoya, Aichi 464-8603 (Japan)
  2. Mitsubishi Heavy Industry ltd., 16-5 Konan 2-chome, Minato-ku, Tokyo 108-8215 (Japan)

The electrostatic acceleration of helicon plasma is investigated using an electrostatic potential exerted between the ring anode at the helicon source exit and an off-axis hollow cathode in the downstream region. In the downstream region, the magnetic field for the helicon source, which is generated by a solenoid coil, is modified using permanent magnets and a yoke, forming an almost magnetic field-free region surrounded by an annular cusp field. Using a retarding potential analyzer, two primary ion energy peaks, where the lower peak corresponds to the space potential and the higher one to the ion beam, are detected in the field-free region. Using argon as the working gas with a helicon power of 1.5 kW and a mass flow rate of 0.21 mg/s, the ion beam energy is on the order of the applied acceleration voltage. In particular, with an acceleration voltage lower than 150 V, the ion beam energy even exceeds the applied acceleration voltage by an amount on the order of the electron thermal energy at the exit of the helicon plasma source. The ion beam energy profile strongly depends on the helicon power and the applied acceleration voltage. Since by this method the whole working gas from the helicon plasma source can, in principle, be accelerated, this device can be applied as a noble electrostatic thruster for space propulsion.

OSTI ID:
22391983
Journal Information:
Applied Physics Letters, Vol. 105, Issue 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English