System studies of rf current drive for MST

Journal Article · Fri Dec 23 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3665021· OSTI ID:21612525

Anderson, J K; Burke, D R; Forest, C B; Goetz, J A; Hendries, E R; Seltzman, A H; Thomas, M A ^[1]; Diem, S ^[2]; Harvey, R W ^[3]; Kaufman, M C ^[1]

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1. Department of Physics, University of Wisconsin, Madison, WI (United States)
2. Oak Ridge National Laboratory, Oak Ridge TN (United States)
3. CompX, Del Mar, CA (United States)

Two rf schemes are being studied on the MST reversed field pinch for their potential in current profile control experiments. MHD modeling has shown that a substantial externally-driven off axis parallel current can improve stability of the dominant core tearing modes. A radially localized axisymmetric population of fast electrons has been observed by SXR emission during LH injection (100kW at 800MHz), and is consistent with CQL3D modeling which predicts a small driven current. Computational work suggests that doubling the input power will statistically improve the LH-induced SXR signal to background ratio, and that about 2MW of injected power (an order of magnitude increase) will drive enough current for stabilization of tearing modes. Additionally, a 1 MW 5.5 GHz electron Bernstein wave (EBW) experiment is under construction, which utilizes a very simple and compact antenna compatible with the demands of the RFP. EBW allows access to electron cyclotron heating and current drive in the overdense plasma. Coupling of the external electromagnetic wave to the EBW has been demonstrated, and initial tests at {approx}100kW power have produced a small, localized xray flux consistent with rf heating and high diffusivity of fast electrons. Computational work is currently underway to answer the very important questions of how much power is required, and what level of electron diffusivity is tolerable, to generate a consequential amount of EBW current.

• OSTI ID: 21612525
• Journal Information: AIP Conference Proceedings, Vol. 1406, Issue 1; Conference: 9. topical conference on radio frequency power in plasmas, Newport (United States), 1-3 Jun 2011; Other Information: DOI: 10.1063/1.3665021; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTENNAS
AXIAL SYMMETRY
BERNSTEIN MODE
C CODES
CHARGED-PARTICLE TRANSPORT
COMPUTERIZED SIMULATION
CONTROL
COUPLING
ECR HEATING
ELECTRIC CURRENTS
ELECTRONS
GHZ RANGE
MAGNETOHYDRODYNAMICS
MST DEVICE
PLASMA
PLASMA SIMULATION
PLASMA WAVES
REVERSE-FIELD PINCH
TEARING INSTABILITY
X RADIATION
CLOSED PLASMA DEVICES
COMPUTER CODES
CURRENTS
ELECTRICAL EQUIPMENT
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EQUIPMENT
FERMIONS
FLUID MECHANICS
FREQUENCY RANGE
HEATING
HIGH-FREQUENCY HEATING
HYDRODYNAMICS
INSTABILITY
IONIZING RADIATIONS
LEPTONS
MECHANICS
OSCILLATION MODES
PINCH DEVICES
PINCH EFFECT
PLASMA HEATING
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RADIATION TRANSPORT
RADIATIONS
REVERSED-FIELD PINCH DEVICES
SIMULATION
SYMMETRY
THERMONUCLEAR DEVICES
TOROIDAL PINCH DEVICES