Numerical modeling of the FRC translation on FRX-C

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6897939

Armstrong, W T; Milroy, R D

Translation of Field-Reversed Configurations (FRCs) is important as a technique for increasing x/sub s/, the ratio of the separatrix radius r/sub s/ to conducting wall radius r/sub w/, and thereby improving FRC confinement. By axially translating the FRC from the formation region into a co-linear region where r/sub w/ and the open flux are properly decreased, an increase in x/sub s/ from the present value on FRX-C of approx. 0.4 to greater than or equal to 0.8 should be possible. The associated change in the volume-averaged beta <..beta..> would be from approx. 0.9 to less than or equal to 0.7 with a commensurate decrease in the density and particle transport at the plasma sparatrix boundary. Increasing x/sub s/ through translation allows maintaining r/sub s/, n, T and R/rho/sub io/ approximately constant, in contrast to in-situ techniques for increasing x/sub s/ (where n is the density, T is the total temperature and R/rho/sub io/ is the ratio of the major radius to ion gyro-radius indexed to the external field). We numerically model FRC formation and translation initiation on FRX-C with a 2-D MHD code which utilizes a continuously-rezoned Lagrangian mesh. Simulation results are presented which indicate adverse effects of DC translation fields on translation initiation. Successful FRC translation appears possible with these effects present. Translation enhancement is examined through passive techniques which require no additional powered coils. In particular, simulation results for the inclusion of a high permeability field divertor to overcome the DC field effects are also presented.

• Research Organization: Los Alamos National Lab., NM (USA); Mathematical Sciences Northwest, Inc., Bellevue, WA (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6897939
• Report Number(s): LA-UR-82-3443; CONF-821124-5; ON: DE83003543
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700200* -- Fusion Energy-- Fusion Power Plant Technology
BETA RATIO
MAGNETIC FIELD CONFIGURATIONS
MATHEMATICAL MODELS
PINCH EFFECT
REVERSE-FIELD PINCH
THETA PINCH
TWO-DIMENSIONAL CALCULATIONS