FRC translation dynamics and plasma confinement properties in FRX-C/T
In the FRX-C/T experiment field-reversed configuration plasmas are translated over 16 meters without inducing instabilities or enhanced transport. The plasmas are formed in either a puff or static D/sub 2/ fill and they are accelerated to axial speeds of up to the ion thermal velocity. The observed acceleration dynamics agree with 2-D MHD simulations. When translated into reduced external magnetic fields, FRCs are observed to accelerate, expand, and cool in approximate agreement with adiabatic theory. The plasmas reflect from an external mirror with negligible loss in thermal energy, particle inventory, and poloidal magnetic flux. After each reflection the axial kinetic energy is reduced by approximately 50%. Because of this reduction, FRCs are readily trapped without the need of pulsed gate magnet coils. Translation has also allowed the scaling of FRC confinement over an extended parameter space with plasma dimensions, temperatures, and densities varying by factors of 2 to 4. An empirical scaling law of the observed nonclassical particle confinement shows departures from the lower-hybrid-drift scaling. Particle transport accounts for approximately one-half of the total energy loss. The confinement parameter, n tau/sub E/ approx. = 10/sup 11/ s/cm/sup 3/, is observed with n approx. = 10/sup 15/ cm/sup -3/ and T/sub i/ approx. = 0.6 keV.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Mathematical Sciences Northwest, Inc., Bellevue, WA (USA)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 6381680
- Report Number(s):
- LA-UR-84-3289; CONF-8411111-2; ON: DE85002386
- Resource Relation:
- Conference: Japan/US joint symposium on compact toroid research, Hiroshima, Japan, 13 Nov 1984
- Country of Publication:
- United States
- Language:
- English
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