ECRH and ICRH in the TMX-U tandem mirror

Conference · Thu Mar 15 04:00:00 EST 1984

OSTI ID:5003365

Stallard, B W; Cummins, W F; Molvik, A W; Poulsen, P; Simonen, T C; Falabella, S; Barter, J D; Christensen, T; Dimonte, G; Romesser, T E

In the Tandem Mirror Experiment Upgrade (TMX-U), the formation of a thermal barrier and the potential plugging of ion end loss were achieved at central-cell densities up to 2 x 10/sup 12/ cm/sup -3/. The presence of a thermal barrier was confirmed by direct measurement, and ion axial-confinement times in the range 50 to 100 ms were measured. The ECRH in the end cells (a) initiates plasma startup, (b) generates hot, mirror-confined electrons to form thermal barriers, and (c) creates the plugging potential for central-cell ions. The ECRH system consists of four 200 kW, 28 GHz gyrotrons each feeding power to a separate heating location (two in each end plug). Fundamental heating is used at the potential plug, and second harmonic is used in the thermal barrier. Hot-electron plasmas are produced at total end-cell antenna power levels up to 300 kW. Strong single-pass absorption and net hot-electron heating efficiencies exceeding 40% are observed. Hot-electron parameters achieved are: n/sub eh//n/sub et/ up to 0.8, volume-average beta <..beta..> approx. = 0.15, and T/sub x/ (x-ray tail above 40 keV) in the range 75 to 200 keV.

• Research Organization: Lawrence Livermore National Lab., CA (USA); California Univ., Davis (USA); TRW, Inc., Redondo Beach, CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5003365
• Report Number(s): UCRL-89423; CONF-840311-5; ON: DE84009681
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101* -- Fusion Energy-- Plasma Research-- Confinement
Heating
&amp; Production
ECR HEATING
END EFFECTS
ENERGY LOSSES
HEATING
HIGH-FREQUENCY HEATING
ICR HEATING
LOSSES
MAGNETIC MIRRORS
OPEN PLASMA DEVICES
PLASMA HEATING
START-UP
TANDEM MIRRORS
THERMAL BARRIERS
THERMONUCLEAR DEVICES
TMX DEVICES