Electrostatic acceleration of helicon plasma using a cusped magnetic field

Journal Article · Mon Nov 10 04:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4900423· OSTI ID:22391983

Harada, S. ^[1]; Baba, T.; Uchigashima, A.; Iwakawa, A.; Yokota, S. ^[1]; Yamazaki, T.; Shimizu, H. ^[2]

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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, Journal Name: Applied Physics Letters Journal Issue: 19 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ARGON
ELECTRONS
HELICON WAVES
HOLLOW CATHODES
ION BEAMS
MAGNETIC FIELDS
PERMANENT MAGNETS
SOLENOIDS