First results from solid state neutral particle analyzer on experimental advanced superconducting tokamak

Area of Science:

• Plasma physics
• Fusion energy research
• Particle diagnostics

Background:

• Tokamak devices are crucial for fusion energy research.
• Accurate measurement of energetic particles is essential for understanding plasma behavior.
• Existing diagnostic tools have limitations in resolution and scope.

Purpose of the Study:

• To implement and evaluate the performance of solid-state neutral particle analyzers (ssNPAs) on the experimental advanced superconducting tokamak.
• To assess the capability of ssNPAs in measuring energetic particles with high temporal and spatial resolution.
• To investigate the response of ssNPAs to different plasma heating and fueling methods.

Main Methods:

• Deployment of compact, full-function integrated solid-state neutral particle analyzers (ssNPAs) utilizing absolute extreme ultraviolet silicon photodiodes.
• Operation of the ssNPA system in advanced current mode.
• Conducting both active and passive charge exchange measurements.
• Analysis of ssNPA signals during neutral beam injection (NBI) and ion cyclotron resonant heating (ICRH).

Main Results:

• ssNPA flux signals increased substantially with neutral beam injection (NBI).
• The horizontal active array responded promptly to modulated NBI, with a weaker response from the passive array.
• Near-tangential NBI resulted in higher passive ssNPA flux and broader profiles compared to near-perpendicular NBI.
• Significantly enhanced ssNPA channel intensities were observed during ion cyclotron resonant heating (ICRH).

Conclusions:

• The implemented ssNPAs provide effective real-time diagnostics for energetic particles in tokamak plasmas.
• ssNPAs demonstrate fast temporal and spatial resolution capabilities crucial for advanced tokamak operations.
• The diagnostic's response varies with NBI geometry and is sensitive to ICRH, offering insights into particle transport and confinement.