Accession Number:

ADA088086

Title:

Electron Cyclotron/Upper Hybrid Resonant Preionization in the ISX-B Tokamak.

Descriptive Note:

Memorandum rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Report Date:

1980-06-20

Pagination or Media Count:

34.0

Abstract:

Preionization experiments have been performed on a tokamak by injecting about 80 kW of microwave power at 35 GHz for up to 15 ms. Microwave absorption occurs at the electron cyclotron and upper hybrid resonance frequencies as predicted by theory. Preionization causes substantial 40 reductions in loop voltage during the initial phase of the tokamak shot. Flux volt second savings with preionization are about 30 in the first 2 ms or about 2 of the total flux expenditure in a tokamak shot. The plasma current starts 20 microsec earlier and rises 1.4 times more rapidly in the preionized case. Electron densities of 5 x 10 to the 12th powercu cm can be sustained with only a toroidal magnetic field during microwave injection. The bulk electron temperature in the preionized plasma is about 10 eV although there are indications of higher electron temperatures 50 eV in the upper hybrid resonance layer. During the early stages of ohmic heating the preionization is effective in decreasing the peak of the radiated power. Author

Subject Categories:

  • Fusion Devices (Thermonuclear)
  • Plasma Physics and Magnetohydrodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE