Ion-beam focusing in a double-plasma device

Author

Johnson, Jobby C. ; D´Angelo, Nicola ; Merlin, Robert L.

Author_Institution

Dept. of Phys. & Astron., Iowa Univ., Iowa City, IA, USA

Volume

16

Issue

5

fYear

1988

fDate

10/1/1988 12:00:00 AM

Firstpage

590

Lastpage

596

Abstract

The authors studied the propagation of a low-energy charge-neutralized ion beam injected into the target region of a long double-plasma device. A magnetic field of up to ~180 G may be applied along the axis of the device. As a result of charge exchange collisions, the ion beam is attenuated as it propagates into the target region. However, under certain conditions of magnetic field strength and neutral gas pressure, the authors have observed a `reemergence´ of the beam on axis far downstream in the target. This reemergence of the ion beam is attributed to a focusing of the ions by a self-consistently produced radial ambipolar electric field. The effect may be expected to occur in other types of plasma devices as well, whenever a sufficiently large radially inward electric field is present

Keywords

Langmuir probes; fluctuations; focusing; ion beams; plasma density; plasma devices; plasma-beam interactions; Langmuir probes; attenuation; charge exchange collisions; density fluctuations; double-plasma device; focusing; low-energy charge-neutralized ion beam; magnetic field; neutral gas pressure; plasma density; radial ambipolar electric field; radially inward electric field; Argon; Astronomy; Atomic beams; Ion beams; Magnetic devices; Magnetic fields; NASA; Physics; Plasma devices; Shape;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.8970

Filename

8970