Real-time reflectometry measurement validation in H-mode regimes for plasma position control

Area of Science:

• Plasma physics
• Fusion energy research
• Control systems engineering

Background:

• Accurate real-time tracking of the plasma separatrix is crucial for controlling fusion devices like ITER.
• Reflectometry electron density profiles are used for separatrix estimation in H-mode regimes.
• Edge Localized Modes (ELMs) can disrupt measurements, impacting control precision.

Purpose of the Study:

• To develop an automated method for removing ELM-affected measurements from plasma position estimation.
• To enhance the reliability and precision of real-time separatrix tracking for ITER.
• To generate an estimate confidence value for feedback control systems.

Main Methods:

• Joint analysis of reflectometry electron density profiles and separatrix density estimates.
• Development of a rejection mechanism to exclude data during ELM collapse and recovery phases.
• Integration of an estimate confidence value into the position feedback controller.

Main Results:

• The proposed method effectively removes ELM-affected measurements from the position estimation procedure.
• Preliminary results demonstrate improved real-time experimental separatrix tracking capabilities.
• The method generates a confidence value that can be utilized by the feedback controller.

Conclusions:

• The automated ELM data rejection method enhances the precision of plasma position control for ITER.
• This approach has the potential to reduce reliance on external ELM event signaling during feedback operation.
• Improved separatrix tracking contributes to more stable and efficient fusion plasma confinement.