Thermal barrier confinement experiments in the TMX-U tandem mirror

Conference · Thu Jul 26 00:00:00 EDT 1984

OSTI ID:6579759

Simonen, T C; Allen, S L; Baldwin, D E; Casper, T A; Clauser, J F; Coensgen, F H; Cohen, R H; Correll, D L; Cummins, W F; Damm, C C

In our recent experiments on the TMX-U thermal-barrier device, we achieved the end plugging of axial ion losses up to a central cell density of n/sub c/ = 6 x 10/sup 12/ cm/sup -3/. During lower density experiments, we measured the axial potential profile characteristic of a thermal barrier and found an ion-confining potential greater than 1.5 kV and a potential depression of 0.45 kV in the barrier region. The average beta of hot end plug electrons has reached 15% and of hot central cell ions has reached 6%. In addition, we heated deuterium ions in the central cell with ICRF to an average perpendicular energy of 2 keV. During strong end plugging at low density (7 x 10/sup 11/ cm/sup -3/), the axial ion confinement time tau/sub parallel/ reached 50 to 100 ms while the nonambipolar radial ion confinement time tau/sub perpendicular/ was 14 ms - independent of end plugging. Electrically floating end walls increased the radial ion confinement time by a factor of 1.8. At higher densities and lower potentials, tau/sub parallel/ was 6 to 12 ms and tau/sub perpendicular/ exceeded 100 ms.

• Research Organization: Lawrence Livermore National Lab., CA (USA); TRW, Inc., Redondo Beach, CA (USA); Maryland Univ., Baltimore (USA); Johns Hopkins Univ., Baltimore, MD (USA); California Univ., Davis (USA); Sandia National Labs., Livermore, CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6579759
• Report Number(s): UCRL-90396; CONF-840910-8; ON: DE84015955
• Conference Information: 10. international conference on plasma physics and controlled nuclear fusion research, London, UK, 12 Sep 1984
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
CONFINEMENT
CONFINEMENT TIME
ELECTRIC POTENTIAL
ENERGY LOSSES
LOSSES
MAGNETIC MIRRORS
OPEN PLASMA DEVICES
PLASMA CONFINEMENT
PLUGGING
TANDEM MIRRORS
THERMAL BARRIERS
THERMONUCLEAR DEVICES
TMX DEVICES