ECH Experiments of ATF

Conference · Mon Aug 12 04:00:00 EDT 1991 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.41690· OSTI ID:5307293

Bigelow, T. S. ^[1]; Wilgen, J. B. ^[1]; Baylor, L. R. ^[1]; Murakami, M. ^[1]; Schaich, C. R. ^[1]; Lindley, R. ^[2]

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1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
2. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); University of Michigan, Ann Arbor, MI (United States)

Several electron cyclotron heating (ECH) experiments have been completed on the Advanced Toroidal Facility (ATF) at Oak Ridge National Laboratory (ORNL) under a variety of operating conditions and launch polarizations. ECH power is launched using a polarization-controlled beam launcher and microwave detectors are used to measure absorption of first-pass and multiply-reflected power. Measurements show that first-pass absorption efficiency at low plasma density is highly dependent on magnetic field, polarization, and plasma conditions. Wave polarization rotation has been detected, it is caused by the large magnetic field shear on ATF. Detector signals indicate that absorption efficiency is relatively high for medium plasma density at either fundamental or second harmonic operation. Plasmas have also been sustained using the third harmonic cyclotron resonance where absorption efficiency is much lower. Gyrotron power modulation and turn-off experiments have been performed to study power deposition and transport using plasma diagnostics. These experiments show that power absorption is fairly efficient. However, the power deposition profile is rather broad despite the relatively narrow launcher beam. This effect can be attributed to several factors including the broad extent of the resonant surface and the {approximately}45% of power contained in both low-level sidelobes outside the launcher beam and in the wrong plasma mode.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Fusion Energy Sciences (FES)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5307293
• Report Number(s): CONF-910869--10; ON: DE91018845
• Conference Information: Journal Name: AIP Conference Proceedings Journal Volume: 244
• 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
AMPLIFIERS
ATF TORSATRON
CLOSED PLASMA DEVICES
ECR HEATING
ELECTRONIC EQUIPMENT
EQUIPMENT
HEATING
HIGH-FREQUENCY HEATING
LEAK DETECTORS
MAGNETIC FIELDS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
PLASMA DENSITY
PLASMA DIAGNOSTICS
PLASMA HEATING
PLASMA WAVES
STELLARATORS
THERMONUCLEAR DEVICES
TORSATRON STELLARATORS