High-fidelity tomographic reconstruction for infrared video bolometers through physics-based background radiation...

Area of Science:

• Nuclear Fusion Science
• Plasma Physics
• Diagnostic Techniques

Background:

• Controlling radiation losses from impurities is crucial for stable fusion plasma operation.
• Infrared video bolometers (IRVBs) visualize radiated power but face limitations with dynamic background radiation.
• Conventional signal processing assumes linear background variation, hindering accurate radiated power profile reconstruction.

Purpose of the Study:

• To develop a novel signal-processing algorithm for accurate radiated power profile reconstruction in fusion plasmas.
• To overcome the limitations of conventional methods in handling time-dependent background radiation.
• To enhance the reliability of impurity transport and power balance analyses.

Main Methods:

• A new signal-processing algorithm based on the heat balance equation was developed.
• The algorithm physically models time-dependent background radiation to isolate its contribution.
• Performance was validated using phantom datasets and synthetic tests simulating various discharge scenarios.

Main Results:

• The proposed method reconstructs radiated power profiles with high accuracy (R2≥0.99) compared to conventional methods.
• Application to Korea Superconducting Tokamak Advanced Research (KSTAR) high-confinement mode discharges showed physically consistent results.
• The algorithm effectively isolates the contribution of time-dependent background radiation.

Conclusions:

• The developed algorithm provides a robust tool for fusion plasma diagnostics.
• It significantly enhances the accuracy of radiated power profile reconstruction.
• This advancement improves the reliability of impurity transport and power balance analyses in fusion research.