Filamentary probe on the COMPASS tokamak

Area of Science:

• Plasma physics
• Fusion energy research
• Tokamak diagnostics

Background:

• Understanding plasma filaments in the scrape-off layer (SOL) is crucial for tokamak operation.
• Previous diagnostic limitations hindered detailed measurement of filament properties and evolution.
• The COMPASS tokamak provides a platform for studying SOL plasma phenomena.

Purpose of the Study:

• To introduce and describe a novel filamentary probe for COMPASS.
• To enable measurement of electrostatic and magnetic properties of plasma filaments.
• To investigate filament behavior as a function of radial distance from the separatrix.

Main Methods:

• A new filamentary probe head mounted on a radial manipulator.
• Shot-to-shot radial movement for statistical and evolutionary measurements.
• Data acquisition for electrostatic and magnetic properties of filaments in the SOL.

Main Results:

• Successful implementation of the filamentary probe on the COMPASS tokamak.
• Demonstrated capability to measure filament properties and their radial dependence.
• Presentation of initial conditional averages of plasma filaments during L-mode.

Conclusions:

• The new filamentary probe is a valuable diagnostic for studying SOL plasma filaments.
• The probe facilitates long-term statistical measurements and analysis of filament evolution.
• This work provides foundational data for understanding plasma transport in tokamaks.