A parametric method for correcting polluted plasma current signal and its application on Keda Torus eXperiment.

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Magnetic Confinement Fusion

Background:

• Plasma current measurements in reversed field pinch (RFP) devices like the Keda Torus eXperiment (KTX) are often contaminated by toroidal magnetic field interference.
• Accurate measurement of plasma current is crucial for understanding and controlling RFP plasma behavior.

Purpose of the Study:

• To develop and validate a parametric method for eliminating background noise from plasma current measurements.
• To improve the accuracy of magnetic field diagnostics in the KTX device.
• To enable a clearer understanding of physical processes in RFP plasmas.

Main Methods:

• A parametric method was developed, modeling the toroidal magnetic field windings, vacuum chamber, and Rogowski coil as a linear time-invariant system.
• A constant frequency response function was derived to predict and subtract the toroidal magnetic field's polluting current component.
• The method was applied to correct poloidal and toroidal magnetic field signals in the KTX device.

Main Results:

• The developed parametric method successfully eliminated background noise from plasma current measurements.
• The method demonstrated greater flexibility and universality compared to traditional proportional compensation techniques.
• Corrected magnetic field signals provided a clearer view of the underlying physical processes in the RFP state.

Conclusions:

• The proposed parametric method offers an effective solution for mitigating toroidal magnetic field interference in plasma current diagnostics.
• This technique is adaptable for time-varying signals and applicable to other magnetic field measurements.
• The improved signal accuracy facilitates better analysis of plasma behavior in RFP devices.