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U.S. Department of Energy
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Electron cyclotron heating on the ISX-B tokamak

Conference ·
OSTI ID:5092301

One experiment on electron cyclotron heating on the Impurity Study Experiment (ISX-b) tokamak has been completed and a second experiment is in progress. In the first experiment, with a gyrotron producing 100 kW at 35 GHz, a heating efficiency greater than 60% was achieved. Unpolarized radiation was launched from the high field side of the tokamak, heating electrons at cyclotron resonance in the center of the plasma. From laser scattering and thermal emission at the second gyroharmonic, the electron temperature, initially 850 eV, increased to 1250 eV at the end of a 15-ms pulse. The second experiment is now in progress, with 180 kW at 28 GHz and a capability of 100-ms pulses. A comparison between polarized and unpolarized radiation, modification of the plasma current profile, and a critical comparison with theory are planned. In this paper, experiments on preionization at the upper hybrid resonance are reported. A plasma with an electron temperature of 10 eV was produced, which is not high enough to reduce impurity radiation. The resistive part of the loop voltage was reduced by preionization. Plans for an experiment to measure electric current induced by electron cyclotron heating are presented, along with a review of the theoretical basis of the current drive.

Research Organization:
Oak Ridge National Lab., TN (USA); Tennessee Univ., Knoxville (USA); JAYCOR, Alexandria, VA (USA); Massachusetts Inst. of Tech., Cambridge (USA)
DOE Contract Number:
W-7405-ENG-26
OSTI ID:
5092301
Report Number(s):
CONF-800932-5
Country of Publication:
United States
Language:
English