A new compact solid-state neutral particle analyser at ASDEX Upgrade: Setup and physics modeling.

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Diagnostic Technology

Background:

• Fast ions play a critical role in heating plasmas in fusion devices.
• Measuring the energy spectra of these fast ions is essential for understanding plasma confinement and stability.
• Existing diagnostics have limitations in spatial and temporal resolution for fast-ion measurements.

Purpose of the Study:

• To introduce and validate a new compact solid-state detector for measuring fast neutral particle energy spectra at ASDEX Upgrade.
• To utilize charge exchange principles for inferring confined fast-ion energy spectra.
• To develop and apply advanced modeling techniques for signal analysis and fast-ion profile reconstruction.

Main Methods:

• Installation and calibration of a new compact solid-state detector at ASDEX Upgrade (AUG).
• Utilizing the charge exchange of fast ions with plasma neutrals to measure energy spectra.
• Employing a 3D Monte Carlo code (F90FIDASIM) with a new module for data modeling and analysis.
• Distinguishing between active (heating beam) and passive signal contributions.

Main Results:

• The new detector demonstrates good signal-to-noise characteristics and energy calibration (40-200 keV).
• It achieves high count rates (up to 140 kcps) and has an active view on a heating beam.
• The developed modeling accurately reproduces measured energy spectra, accounting for passive contributions.
• Reconstruction of the birth profile of fast neutrals is achieved.

Conclusions:

• The new solid-state detector is a valuable diagnostic for fast neutral particle energy spectrum measurements at AUG.
• Advanced modeling techniques enable accurate reconstruction of fast-ion velocity distributions and birth profiles.
• This diagnostic and modeling approach enhances the understanding of fast-ion behavior in fusion plasmas.