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Magnetic diagnostics for equilibrium reconstructions with eddy currents on the Lithium Tokamak eXperiment
J C Schmitt1, J Bialek2, S Lazerson1
1Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA.
The Review of Scientific Instruments
|November 29, 2014
Summary
The Lithium Tokamak eXperiment uses advanced magnetic diagnostics to study how eddy currents affect plasma equilibrium reconstruction. This research improves understanding of tokamak performance in fusion energy development.
Area of Science:
- Plasma Physics
- Fusion Energy Engineering
- Magnetic Confinement Fusion
Background:
- The Lithium Tokamak eXperiment (LTX) features a unique low-recycling wall with lithium layers on a copper shell.
- Transient plasma and coil currents induce long-lived eddy currents in the LTX shell and vacuum vessel.
- These eddy currents significantly impact plasma behavior and magnetic diagnostic signals crucial for equilibrium reconstruction.
Purpose of the Study:
- To detail newly installed magnetic diagnostics for LTX, suitable for high-temperature and lithium environments.
- To present axisymmetric (2D) and non-axisymmetric (3D) computational methods for analyzing eddy currents.
- To investigate the influence of eddy currents on plasma equilibrium reconstruction in LTX.
Main Methods:
- Installation and description of re-entrant magnetic diagnostics and internal saddle flux loops.
- Development and application of 2D and 3D numerical models to simulate eddy current effects.
- Utilizing magnetic diagnostic signals, accounting for eddy current influences, for equilibrium reconstruction algorithms.
Main Results:
- The new diagnostics are validated for high-temperature, lithium-rich tokamak conditions.
- Eddy current effects on magnetic signals and plasma equilibrium are quantified using 2D and 3D models.
- Improved accuracy in equilibrium reconstruction is achieved by incorporating eddy current models.
Conclusions:
- Advanced magnetic diagnostics and sophisticated eddy current modeling are essential for accurate plasma control in tokamaks like LTX.
- Understanding and mitigating eddy current impacts are critical for advancing magnetic confinement fusion research.
- The LTX experiment provides valuable data and methodologies for future fusion reactor designs.
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