MHD marking using the MSE polarimeter optics in ILW JET plasmas

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Diagnostic Techniques

Background:

• Magnetohydrodynamics (MHD) phenomena are crucial in high-temperature plasmas.
• Existing diagnostic methods for MHD in such regimes have limitations.
• The JET Motional Stark Effect (MSE) diagnostic offers potential for novel applications.

Purpose of the Study:

• To propose and validate a novel diagnostic technique for polarimetry marking of MHD in high-temperature plasmas.
• To demonstrate the feasibility of using JET MSE diagnostic optics for this purpose.
• To interpret experimental data for understanding MHD behavior.

Main Methods:

• Utilizing the collection optics of the JET Motional Stark Effect (MSE) diagnostic.
• Performing polarimetry marking of observed MHD activity.
• Measuring coherence between MSE polarimeter, electron cyclotron emission, and Mirnov coil signals.
• Analyzing amplitude fluctuations of raw MSE polarimeter signals correlated with MHD frequencies.

Main Results:

• Demonstrated feasibility of the proposed polarimetry marking technique.
• Presented measurements showing coherence between different diagnostic signals.
• Showcased analysis of MSE signal amplitude fluctuations linked to MHD frequencies.
• Provided experimental examples from JET ITER-Like Wall (ILW) plasmas.

Conclusions:

• The novel diagnostic technique using JET MSE optics is feasible for polarimetry marking of MHD.
• The method provides a new way to study MHD phenomena in high-temperature plasmas.
• Experimental validation in JET ILW plasmas supports the technique's interpretation and application.