Fast-ion D-alpha diagnostic development for the C-2W field-reversed configuration plasma

Area of Science:

• Plasma Physics
• Fusion Energy Research
• Spectroscopy

Background:

• TAE Technologies's C-2W device features a significant fast-ion population, crucial for fusion energy studies.
• Fast-Ion D-alpha (FIDA) spectroscopy is a key diagnostic for understanding fast-ion behavior in plasmas.
• Previous FIDA measurements and C-2W geometry data guided the spectrometer's design.

Purpose of the Study:

• To develop and design a FIDA spectrometer system for the C-2W fusion device.
• To identify optimal diagnostic ports for maximizing FIDA signal detection.
• To enable detailed studies of fast-ion populations and their dynamics.

Main Methods:

• Utilizing experimental 1D plasma profiles from C-2U and mapping them onto Q2D simulation flux surfaces.
• Employing the FIDASIM code to simulate FIDA spectra for numerous lines-of-sight (LOSs) and neutral beam paths.
• Selecting hardware, including a high-speed camera and spectrograph, based on measured signal levels and simulation predictions.

Main Results:

• Simulations identified specific ports with large predicted FIDA signals by considering 354 potential viewing locations.
• The design incorporates a high-speed camera and a custom spectrograph optimized for FIDA measurements.
• The methodology allows for the integration over wavelength and beam-space to select optimal measurement ports.

Conclusions:

• The developed FIDA spectrometer design is optimized for the C-2W device's specific geometry and plasma conditions.
• The study successfully integrated simulation and experimental data to guide the selection of diagnostic components and locations.
• This work lays the foundation for advanced fast-ion studies using FIDA spectroscopy on the C-2W device.