New signal processing technique for density profile reconstruction using reflectometry.

Area of Science:

• Plasma physics
• Fusion energy research
• Diagnostic techniques

Background:

• Accurate plasma profile measurement is crucial for fusion research.
• Reflectometry requires precise signal analysis for reliable data.
• Existing methods face challenges with signal separation and noise.

Purpose of the Study:

• To introduce and validate a novel data processing technique for reflectometry.
• To enhance the accuracy and reliability of plasma density profile measurements.
• To improve signal isolation in complex tokamak environments.

Main Methods:

• Application of time-frequency tomographic representation for data analysis.
• Processing of signals from two distinct reflectometer devices on the Tore Supra tokamak.
• Evaluation of improved signal separation and component isolation.

Main Results:

• Enhanced initialization and reliability for standard density profile reflectometry.
• Accurate density measurements in the far scrape-off layer (down to 10^16 m^-3).
• Improved separation of plasma signals from multi-reflections near a lower hybrid launcher.

Conclusions:

• The time-frequency tomographic method significantly improves reflectometry data analysis.
• This technique offers more reliable and accurate plasma density measurements.
• It is effective for diverse reflectometer configurations in fusion devices.