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Title: Test wave harmonics generation in an inhomogeneous plasma with an electron beam and a return current

Abstract

Generation of second and third harmonics of a pump wave, taking place during electron beam propagation in a plasma with a return current, is investigated. Polarization properties and generation efficiency are specifically addressed. Analytical dependencies of the investigated physical values are reported for both the cases when the generation mechanism is provided by collisions of beam electrons with plasma ions, and when it is provided by collisions of bulk electrons creating the return current.

Authors:
; ;  [1];  [2];  [3]
  1. Dipartimento di Fisica e Tecnologie Relative, Universita di Palermo, Viale delle Scienze, Edificio 18, I-90128 Palermo (Italy)
  2. (Russian Federation)
  3. (Italy)
Publication Date:
OSTI Identifier:
20860459
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 13; Journal Issue: 12; Other Information: DOI: 10.1063/1.2403093; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM-PLASMA SYSTEMS; EFFICIENCY; ELECTRIC CURRENTS; ELECTRON BEAMS; ELECTRON COLLISIONS; ELECTRONS; HARMONICS; INHOMOGENEOUS PLASMA; ION COLLISIONS; IONS; POLARIZATION; RADIATION TRANSPORT

Citation Formats

Ferrante, G., Uryupin, S. A., Batani, D., P. N. Lebedev Physical Institute, Leninsky pr. 53, 119991, Moscow, and Dipartimento di Fisica 'G. Occhialini', Universita di Milano Bicocca, Piazza della Scienza 3, I-20126 Milan. Test wave harmonics generation in an inhomogeneous plasma with an electron beam and a return current. United States: N. p., 2006. Web. doi:10.1063/1.2403093.
Ferrante, G., Uryupin, S. A., Batani, D., P. N. Lebedev Physical Institute, Leninsky pr. 53, 119991, Moscow, & Dipartimento di Fisica 'G. Occhialini', Universita di Milano Bicocca, Piazza della Scienza 3, I-20126 Milan. Test wave harmonics generation in an inhomogeneous plasma with an electron beam and a return current. United States. doi:10.1063/1.2403093.
Ferrante, G., Uryupin, S. A., Batani, D., P. N. Lebedev Physical Institute, Leninsky pr. 53, 119991, Moscow, and Dipartimento di Fisica 'G. Occhialini', Universita di Milano Bicocca, Piazza della Scienza 3, I-20126 Milan. Fri . "Test wave harmonics generation in an inhomogeneous plasma with an electron beam and a return current". United States. doi:10.1063/1.2403093.
@article{osti_20860459,
title = {Test wave harmonics generation in an inhomogeneous plasma with an electron beam and a return current},
author = {Ferrante, G. and Uryupin, S. A. and Batani, D. and P. N. Lebedev Physical Institute, Leninsky pr. 53, 119991, Moscow and Dipartimento di Fisica 'G. Occhialini', Universita di Milano Bicocca, Piazza della Scienza 3, I-20126 Milan},
abstractNote = {Generation of second and third harmonics of a pump wave, taking place during electron beam propagation in a plasma with a return current, is investigated. Polarization properties and generation efficiency are specifically addressed. Analytical dependencies of the investigated physical values are reported for both the cases when the generation mechanism is provided by collisions of beam electrons with plasma ions, and when it is provided by collisions of bulk electrons creating the return current.},
doi = {10.1063/1.2403093},
journal = {Physics of Plasmas},
number = 12,
volume = 13,
place = {United States},
year = {Fri Dec 15 00:00:00 EST 2006},
month = {Fri Dec 15 00:00:00 EST 2006}
}
  • The properties of an intense annular relativistic electron beam generated by a ring cathode and conical anode have been studied in detail. The beam is injected into a channel between concentric cones (containing a neutral gas for space charge and current neutralization) where it is transported and focused. Half of the return current is then fed back through the cathode to prevent radial pinching of the primary current sheet. On the Sandia Reba accelerator which generated a beam of about 120 kA at 1 MeV an area compression of 10 was achieved with 50% efficiency. The compressibility of the beammore » was found to depend primarily on the azimuthal temperature of the beam as it emerged from the diode and on the diode plasma closure rate. (auth)« less
  • It is found experimentally that in a comparatively dense plasma (n/sub p/>10/sup 12/ cm/sup -3/) the return current induced by a relativistic electron beam in a plasma decays because of a lack of electron emission from the collector. At densities n/sub p/<10/sup 12/ cm/sup -3/ the decay of the return current is independent of the emissivity of the collector, apparently due to a strong beam--plasma interaction. A plasma collector which is a prolific emitter can be produced by means of an external source (the spark source operates 1 ..mu..sec before the relativistic electron beam is injected), or it can bemore » produced by the relativistic electron beam itself, through an interaction of this beam with the collector material. In the first case the return current does not decay if n/sub p/>10/sup 12/ cm/sup -3/; in the second case, there is a partial disruption of the return current. The degree of residual current neutralization increases with increasing beam current.« less
  • The stationary states of a cylindrical axisymmetric electron beam in a cylindrical plasma-filled channel are analyzed by kinetic theory. In contrast with earlier work on the subject, it is assumed that return current flows in the channel. The radial profiles of the charge and current of the components of the system (the beam electrons, the plasma electrons, and the plasma ions) are found for beam radii smaller than, equal to, and larger than the channel radius. If the channel radius is larger than or equal to the beam radius, and the skin depth of the beam is smaller than halfmore » the beam radius, the current carried by the beam in a given stationary state is higher than that carried by the neutralized electron beam.« less