Extensions to the charge exchange recombination spectroscopy diagnostic suite at ASDEX Upgrade

Area of Science:

• Fusion energy research
• Plasma physics
• Spectroscopy diagnostics

Background:

• Accurate plasma diagnostics are crucial for understanding and controlling fusion devices.
• Previous methods had limitations in spatial resolution and coverage for core plasma measurements.

Purpose of the Study:

• To introduce and characterize a new core charge exchange recombination spectroscopy diagnostic for the ASDEX Upgrade tokamak.
• To enable simultaneous measurement of impurity ion temperature, toroidal rotation, and density on both low field side (LFS) and high field side (HFS).

Main Methods:

• Installation of a new diagnostic system with 48 lines-of-sight (LOS).
• Utilizing flexible-wavelength spectrometers for simultaneous impurity measurements.
• Achieving high radial resolution (±2 cm LFS to ±0.75 cm HFS) and fast time resolution (down to 2.5 ms).

Main Results:

• The diagnostic provides detailed LFS-HFS impurity ion temperature and toroidal rotation profiles.
• High-quality rotation profiles allow for extraction of poloidal velocity information from LFS-HFS asymmetry.
• The system demonstrates routine operation at 10 ms integration time with potential for faster measurements.

Conclusions:

• The new diagnostic significantly enhances the capabilities for core plasma characterization in the ASDEX Upgrade tokamak.
• It provides crucial data for magnetic equilibrium reconstruction and understanding plasma dynamics.
• This advancement contributes to the development of future fusion energy reactors.