Advances, Challenges, and Future Perspectives of Microwave Reflectometry for Plasma Position and Shape Control on...

Area of Science:

• Nuclear Engineering
• Plasma Physics
• Radio Science

Background:

• Fusion energy development faces grand challenges in efficient, economical, and environmentally benign scaling.
• Real-time control of burning plasma is critical for fusion energy.
• Plasma Position Reflectometry (PPR) is vital for monitoring plasma position and shape in next-generation fusion reactors.

Purpose of the Study:

• To develop and test Plasma Position Reflectometry (PPR) systems for future fusion machines like DEMO.
• To address engineering and physics challenges in designing PPR diagnostics using radio science techniques.
• To ensure the reliability and replaceability of diagnostic systems under harsh neutron irradiation environments in DEMO.

Main Methods:

• Utilizing radar science methods in microwave and millimeter wave frequencies for plasma diagnostics.
• Measuring radial edge density profiles at multiple poloidal angles for feedback control.
• Developing compact, fast-frequency sweeping RF back-ends using Monolithic Microwave Integrated Circuits (MMICs).

Main Results:

• Proof of concept for PPR demonstrated in ASDEX-Upgrade and COMPASS.
• Design advancements for ITER and DEMO, considering integration challenges like the diagnostics slim cassette (DSC).
• Development of compact MMIC-based RF back-ends for efficient signal processing.

Conclusions:

• PPR is crucial for real-time plasma control in future fusion devices.
• The Divertor Test Tokamak (DTT) is a key facility for PPR system development and testing.
• Ongoing advancements in electronics and integration are essential for successful PPR implementation in DEMO and beyond.