Heavy ion beam probe coordinate mapping and calibration at WEGA stellarator

Area of Science:

• Plasma physics
• Fusion energy research
• Diagnostic techniques

Background:

• Heavy ion beam probe (HIBP) is a diagnostic tool for measuring plasma parameters like potential, density, and temperature in magnetically confined plasmas.
• Accurate coordinate mapping of the HIBP measurement point is crucial for reliable data but challenging due to modeling complexities.
• Conventional ray tracing methods may not fully account for all physical effects, leading to discrepancies in probing position.

Purpose of the Study:

• To enhance the precision of coordinate mapping for HIBP diagnostics.
• To validate and refine ray tracing calculations used for HIBP measurements.
• To develop a calibration method applicable to various fusion experiments.

Main Methods:

• Implementing a primary beam detector array within the vacuum vessel to measure the actual ion beam position.
• Comparing measured beam positions with those predicted by ray tracing calculations.
• Utilizing discrepancies to adjust and improve the accuracy of the HIBP coordinate mapping code.

Main Results:

• Demonstrated a method for precise calibration of HIBP measurement points.
• Validated the accuracy of ray tracing calculations through experimental comparison.
• Successfully improved the coordinate matching for HIBP on the WEGA stellarator.

Conclusions:

• The developed calibration technique significantly improves HIBP coordinate mapping accuracy.
• This method offers a practical approach to refine diagnostic positioning in magnetic confinement fusion.
• The calibration principle is adaptable for enhancing HIBP diagnostics in other experimental setups.