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Plasma Production and Heating in the Superconducting Levitron

Abstract

Plasma production and heating in the Superconducting Levitron are described. The device has a floating superconducting ring with 40-cm major radius and 5-cm minor radius, which carries up to 600 kA current. Toroidal field is provided by a current of up to 1 MA. Six poloidal field coils are used to shape the magnetic surfaces to obtain field configurations with strong shear and with minimum average B, a local minimum -B well, or minimum {partial_derivative}B/{partial_derivative}s ({delta}B/B Less-Than-Or-Equivalent-To 0.005 - 0.05). Large area surfaces at liquid helium temperature which are not directly exposed to the plasma provide ultrahigh vacuum. Methods of production and heating of dense plasma with appreciable {beta} have been studied using a classical diffusion and thermal conduction model, which includes trapped-particle effects. Computations have been made both for heating by an initial hot electron plasma and for energetic neutral injection. The latter technique yields n Almost-Equal-To 10{sup 13} cm{sup -3}, T{sub e} Almost-Equal-To T{sub i} Almost-Equal-To 0.3 to 0.8 keV with existing sources (200 mA equivalent current at 2 keV). Production and heating by energetic electrons proceeds in two steps: First, a hot electron plasma with n Almost-Equal-To 10{sup 11} to 10{sup 13} cm{sup -3}, T{sub e}, hot  More>>
Authors:
Anderson, O. A.; Birdsall, D. H.; Hartman, C. W.; Hooper, Jr., E. B.; Munger, R. H.; Taylor, C. E. [1] 
  1. Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)
Publication Date:
Oct 15, 1971
Product Type:
Conference
Report Number:
IAEA-CN-28/A-8
Resource Relation:
Conference: 4. International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Madison, WI (United States), 17-23 Jun 1971; Other Information: 13 refs., 8 figs., 2 tabs.; Related Information: In: Plasma Physics and Controlled Nuclear Fusion Research 1971. Vol. I. Proceedings of the Fourth International Conference on Plasma Physics and Controlled Nuclear Fusion Research| 708 p.
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CALCULATION METHODS; CRYOGENIC FLUIDS; DIFFUSION; ECR HEATING; ELECTRIC CURRENTS; HELIUM; KEV RANGE; MAGNETIC SURFACES; MICROWAVE RADIATION; NEUTRAL ATOM BEAM INJECTION; PLASMA PRODUCTION; PRESSURE RANGE BELOW 1 NANO PA; PULSES; SHEAR; SUPERCONDUCTING DEVICES; TAIL ELECTRONS; THERMAL CONDUCTION; THERMONUCLEAR IGNITION; TOKAMAK DEVICES; TRAPPING
OSTI ID:
22127453
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M2866082532
Submitting Site:
INIS
Size:
page(s) 103-115
Announcement Date:
Sep 12, 2013

Citation Formats

Anderson, O. A., Birdsall, D. H., Hartman, C. W., Hooper, Jr., E. B., Munger, R. H., and Taylor, C. E. Plasma Production and Heating in the Superconducting Levitron. IAEA: N. p., 1971. Web.
Anderson, O. A., Birdsall, D. H., Hartman, C. W., Hooper, Jr., E. B., Munger, R. H., & Taylor, C. E. Plasma Production and Heating in the Superconducting Levitron. IAEA.
Anderson, O. A., Birdsall, D. H., Hartman, C. W., Hooper, Jr., E. B., Munger, R. H., and Taylor, C. E. 1971. "Plasma Production and Heating in the Superconducting Levitron." IAEA.
@misc{etde_22127453,
title = {Plasma Production and Heating in the Superconducting Levitron}
author = {Anderson, O. A., Birdsall, D. H., Hartman, C. W., Hooper, Jr., E. B., Munger, R. H., and Taylor, C. E.}
abstractNote = {Plasma production and heating in the Superconducting Levitron are described. The device has a floating superconducting ring with 40-cm major radius and 5-cm minor radius, which carries up to 600 kA current. Toroidal field is provided by a current of up to 1 MA. Six poloidal field coils are used to shape the magnetic surfaces to obtain field configurations with strong shear and with minimum average B, a local minimum -B well, or minimum {partial_derivative}B/{partial_derivative}s ({delta}B/B Less-Than-Or-Equivalent-To 0.005 - 0.05). Large area surfaces at liquid helium temperature which are not directly exposed to the plasma provide ultrahigh vacuum. Methods of production and heating of dense plasma with appreciable {beta} have been studied using a classical diffusion and thermal conduction model, which includes trapped-particle effects. Computations have been made both for heating by an initial hot electron plasma and for energetic neutral injection. The latter technique yields n Almost-Equal-To 10{sup 13} cm{sup -3}, T{sub e} Almost-Equal-To T{sub i} Almost-Equal-To 0.3 to 0.8 keV with existing sources (200 mA equivalent current at 2 keV). Production and heating by energetic electrons proceeds in two steps: First, a hot electron plasma with n Almost-Equal-To 10{sup 11} to 10{sup 13} cm{sup -3}, T{sub e}, hot Almost-Equal-To 100 to 500 keV is established by electron cyclotron resonance heating (ECRH). Second, dense plasma is formed by injection of a short pulse (50 {mu}s) of neutral gas. The inherent cutoff limit of direct ECRH is thereby overcome. Numerical computations of the subsequent in situ heating by energetic electrons predict T{sub i} = 0,14 to 2.0 keV, n = 5 x 10{sup 13} to 10{sup 14} cm{sup -3} for B{sub poloidal} = 1.5 to 6 kG. Thus, heating and ion temperatures comparable to or greater than obtained in the Tokamak T-3 device are predicted. This technique allows scaling to ignition temperature for a D-T plasma using available microwave power sources and a somewhat larger device. (author)}
place = {IAEA}
year = {1971}
month = {Oct}
}