Angular filter refractometry analysis using simulated annealing

Area of Science:

• Plasma Physics
• Laser-Plasma Interactions
• Optical Diagnostics

Background:

• Angular filter refractometry (AFR) is a key diagnostic for laser-produced plasmas.
• Characterizing density profiles of long-scale-length plasmas is crucial for fusion energy research.
• Existing analysis methods for AFR can be limited in accuracy and scope.

Purpose of the Study:

• To develop a novel, robust analysis method for angular filter refractometry (AFR) images.
• To improve the accuracy and reduce uncertainty in determining plasma density profiles.
• To apply the new analysis technique to experimental data from laser-irradiated targets.

Main Methods:

• Development of an annealing algorithm for iterative image analysis.
• Construction of synthetic AFR images based on user-defined density profiles (eight parameters).
• Optimization using the minimization of the chi-squared (χ²) test statistic for parameter convergence and uncertainty calculation.

Main Results:

• Successful application of the annealing algorithm to experimental AFR data.
• Accurate characterization of plasma density profiles from a flat, laser-irradiated target.
• Achieved an average uncertainty of 5%-20% in the plasma density profile within the region of interest.

Conclusions:

• The novel annealing algorithm provides a reliable method for analyzing AFR images.
• This technique significantly enhances the characterization of laser-produced plasma density profiles.
• The method offers a valuable tool for future research in high-energy-density physics and inertial confinement fusion.