Charge and current neutralization in the formation of ion rings in a background plasma

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870487· OSTI ID:6958947

Oliver, B V; Ryutov, D D; Sudan, R N ^[1]

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1. Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States)

For typical field-reversed ion ring experiments, an intense ion beam is injected across a plasma-filled magnetic cusp and propagated into a solenoidal field downstream. The characteristic time [tau] satisfies 2[pi]/[Omega][sub [ital e]][much lt][tau][le]2[pi]/[Omega][sub [ital i]] and the background plasma can be modeled as an electron magnetohydrodynamic (EMHD) fluid. In the nearly collisionless regime, such that [nu][sub [ital e]][much lt][Omega][sub [ital e]], the plasma response is governed by the whistler mode. The role of the wall boundaries in such experiments to control the charge and current neutralization of the injected beam is considered for axisymmetric [partial derivative]/[partial derivative][theta]=0 geometry. It is found that for close enough conducting walls, such that the whistler transit time to the wall is short compared to the beam transit time, effective control of the return currents can be established such that current neutralization can be suppressed while maintaining good charge neutralization ([nu][sub [ital e]] is the electron collision frequency and [Omega][sub [ital e]] is the corresponding gyrofrequency).

• DOE Contract Number: FG02-93ER54221
• OSTI ID: 6958947
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:10; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
BEAM INJECTION
BEAM-PLASMA SYSTEMS
BEAMS
CURRENTS
INSTABILITY
ION BEAMS
ION RINGS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
WALL EFFECTS
WHISTLER INSTABILITY