A 130 point Nd:YAG Thomson scattering diagnostic on MAST

Area of Science:

• Plasma physics
• Fusion energy research
• Diagnostic instrumentation

Background:

• The Mega Ampere Spherical Tokamak (MAST) requires advanced diagnostics for studying plasma behavior.
• Understanding edge and core plasma physics is crucial for fusion energy development.

Purpose of the Study:

• To implement a Thomson scattering diagnostic system on MAST.
• To enable flexible, high-speed measurements of plasma properties.
• To facilitate rapid data acquisition for real-time analysis.

Main Methods:

• Utilized eight Nd:YAG lasers with adjustable repetition rates for burst measurements.
• Employed a large-aperture, multi-element lens system (F/6, 290 mm aperture) for light collection.
• Transferred scattered light via 130 fiber bundles to 130 polychromators.
• Implemented a distributed data acquisition system with 26 chassis, each processing data for five polychromators.

Main Results:

• Successfully implemented a Thomson scattering diagnostic capable of measuring both edge and core plasma physics.
• Achieved arbitrary relative and absolute timing of lasers for tailored measurement bursts.
• Developed a data acquisition system providing quick data availability post-MAST shot.
• Demonstrated potential for real-time data operations.

Conclusions:

• The new Thomson scattering diagnostic enhances MAST's capability to study plasma physics.
• The system's flexibility and speed support detailed investigations of time-evolving plasma phenomena.
• The rapid data processing paves the way for future real-time control applications in fusion devices.