skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Counterstreaming-ion tokamak fusion reactors

Abstract

Tokamak plasmas fueled and heated by energetic neutral-atom beams are characterized by total ion pressure greatly exceeding the electron pressure. For smaller devices with relatively low injection energy, the largest fusion reactivity of energetic-ion plasmas is obtained when oppositely injected D/sup 0/ and T/sup 0/ beams sustain large densities of counterstreaming deuterons and tritons (CIT mode). In this study steady-state ion velocity distributions for the CIT are calculated with a multi-species Fokker-Planck code, and are found to have sufficient thermal spread so that all infinite-medium velocity-space modes are stable. Quasi-stationary operation seems physically realizable, because the injected beams provide all fueling, and the counterstreaming ions can be made to carry the bulk of the plasma current required for equilibrium; a satisfactory magnetic flux-surface configuration is revealed by a particle simulation code. Steady-state radial profiles of plasma parameters are determined with a coupled Fokker-Planck/radial transport code that includes charge-exchange effects and particle and heat diffusion of ''warm'' ions and electrons. With inclusion of realistic charge-exchange loss and a significant warm-ion population, the ideal CIT Q-values are found to be reduced by 60 to 70 percent for a given (n/sub e/tau/sub Ee/). For example, Q = 1.0 for W/sub inj/ = 80more » keV (D/sup 0/) and 120 keV (T/sup 0/), when (n/sub e/tau/sub Ee/) = 8 x 10/sup 12/ cm/sup -3/s and (n/sub hot//n/sub e/) approximately equal to 0.7. Generally, the total ion pressure is 3 to 5 times the electron pressure, and the warm-ion temperature approximately 2T/sub e/.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Princeton Univ., N.J. (USA). Plasma Physics Lab.
OSTI Identifier:
7140892
Report Number(s):
PPPL-1278; CONF-761012-22
TRN: 77-000898
DOE Contract Number:  
E(11-1)-3073
Resource Type:
Conference
Resource Relation:
Conference: 6. international conference on plasma physics and controlled nuclear fusion research, Berchtesgaden, F.R. Germany, 6 Oct 1976
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; TOKAMAK TYPE REACTORS; NEUTRAL ATOM BEAM INJECTION; FOKKER-PLANCK EQUATION; PLASMA PRESSURE; PLASMA SIMULATION; TRANSPORT THEORY; BEAM INJECTION; DIFFERENTIAL EQUATIONS; EQUATIONS; THERMONUCLEAR REACTORS; 700101* - Fusion Energy- Plasma Research- Confinement, Heating, & Production

Citation Formats

Jassby, D. L., Kulsrud, R. M., Perkins, F. W., Killeen, J., Marx, K. D., McCoy, M. G., Mirin, A. A., Rensink, M. E., and Tull, C. G. Counterstreaming-ion tokamak fusion reactors. United States: N. p., 1976. Web.
Jassby, D. L., Kulsrud, R. M., Perkins, F. W., Killeen, J., Marx, K. D., McCoy, M. G., Mirin, A. A., Rensink, M. E., & Tull, C. G. Counterstreaming-ion tokamak fusion reactors. United States.
Jassby, D. L., Kulsrud, R. M., Perkins, F. W., Killeen, J., Marx, K. D., McCoy, M. G., Mirin, A. A., Rensink, M. E., and Tull, C. G. 1976. "Counterstreaming-ion tokamak fusion reactors". United States. https://www.osti.gov/servlets/purl/7140892.
@article{osti_7140892,
title = {Counterstreaming-ion tokamak fusion reactors},
author = {Jassby, D. L. and Kulsrud, R. M. and Perkins, F. W. and Killeen, J. and Marx, K. D. and McCoy, M. G. and Mirin, A. A. and Rensink, M. E. and Tull, C. G.},
abstractNote = {Tokamak plasmas fueled and heated by energetic neutral-atom beams are characterized by total ion pressure greatly exceeding the electron pressure. For smaller devices with relatively low injection energy, the largest fusion reactivity of energetic-ion plasmas is obtained when oppositely injected D/sup 0/ and T/sup 0/ beams sustain large densities of counterstreaming deuterons and tritons (CIT mode). In this study steady-state ion velocity distributions for the CIT are calculated with a multi-species Fokker-Planck code, and are found to have sufficient thermal spread so that all infinite-medium velocity-space modes are stable. Quasi-stationary operation seems physically realizable, because the injected beams provide all fueling, and the counterstreaming ions can be made to carry the bulk of the plasma current required for equilibrium; a satisfactory magnetic flux-surface configuration is revealed by a particle simulation code. Steady-state radial profiles of plasma parameters are determined with a coupled Fokker-Planck/radial transport code that includes charge-exchange effects and particle and heat diffusion of ''warm'' ions and electrons. With inclusion of realistic charge-exchange loss and a significant warm-ion population, the ideal CIT Q-values are found to be reduced by 60 to 70 percent for a given (n/sub e/tau/sub Ee/). For example, Q = 1.0 for W/sub inj/ = 80 keV (D/sup 0/) and 120 keV (T/sup 0/), when (n/sub e/tau/sub Ee/) = 8 x 10/sup 12/ cm/sup -3/s and (n/sub hot//n/sub e/) approximately equal to 0.7. Generally, the total ion pressure is 3 to 5 times the electron pressure, and the warm-ion temperature approximately 2T/sub e/.},
doi = {},
url = {https://www.osti.gov/biblio/7140892}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1976},
month = {9}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: