Particle-In-Cell Simulation of Ion Beam Neutralization by a Tenuous Background Plasma
Authors: William Berdanier and Igor Kaganovich
Abstract:
The neutralization and focusing of intense charged particle beam pulses by electrons forms the
basis for a wide range of applications for accelerators, heavy ion fusion, and astrophysics. For intense
ion beam pulses, a background plasma can be used to e ectively neutralize the beam charge and
current, thereby neutralizing the self- elds. We show that even a tenuous background plasma with a
small relative density can achieve high neutralization. Using the Large Scale Plasma (LSP) particle-
in-cell code, the interaction of an intense ion beam with an underdense plasma was simulated. It was
shown that if the total plasma electron charge is comparable to the beam charge, electron emitters
are necessary for e ective neutralization. These are not needed if the plasma volume is large. A
variety of plasma densities was investigated, including the case of emitters without plasma, which
did not e ectively neutralize the beam. Over 95% neutralization was found for even very tenuous
background plasma, in agreement with earlier analytical studies.
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Submitted to: 53rd Annual Meeting of the APS Division of Plasma Physics, November 14-18, 2011, Salt Lake City, Utah.
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Download PPPL-4679 (pdf 4.12MB 12 pp)
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