Measurements of ECH absorption on ATF using a polarization-controlled beam launcher

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6244282

Bigelow, T S; Schaich, C R; White, T L

Electron cyclotron heating (ECH) is used on the Advanced Toroidal Facility (ATF) experiment at ORNL for plasma formation and heating. A 53.2 GHz gyrotron generates 200 kW cw which is transported to ATF in 6.35 cm evacuated waveguide. Power is launched into ATF using a recently completed polarization controlled beam launcher which can launch a linear polarized beam with a /minus/20 dB diameter of 12 cm at the plasma center. The launcher consists of a Vlasov mode converting antenna, a Teflon-copper laminate polarization rotating grating, and a spherical focusing mirror. The plane of polarization can be remotely adjusted by rotating the grating with a motorized vacuum feedthrough. First pass plasma absorption is monitored in two planes of polarization using a dual-polarized detector looking through a dome shaped scattering cut-off screen. During plasma operation, the detected signals indicate that absorption under ideal conditions is nearly complete. With low density or a shifted resonance zone, absorption is small and there are cases where there is mode coupling to the perpendicular polarization. This is presumably due to shear in the ATF magnetic field. 2 refs., 3 figs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6244282
• Report Number(s): CONF-890403-16; ON: DE89012501
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700205* -- Fusion Power Plant Technology-- Fuel
Heating
& Injection Systems
ABSORPTION
ATF TORSATRON
BEAMS
CLOSED PLASMA DEVICES
DESIGN
ECR HEATING
HEATING
HIGH-FREQUENCY HEATING
MAGNETIC FIELDS
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA HEATING
POLARIZED BEAMS
STELLARATORS
THERMONUCLEAR DEVICES
TORSATRON STELLARATOR
WAVE FORMS
WAVEGUIDES