Complex interferometry of magnetized plasma: accuracy and limitations

TL;DR

This paper analyzes the accuracy and limitations of complex interferometry techniques for diagnosing magnetized plasmas, focusing on error sources and providing a framework for reliable plasma density and magnetic field measurements.

Contribution

It offers a detailed analysis of error sources in complex interferometry for magnetized plasma diagnostics, including a universal approach using synthetic profiles and real data examples.

Findings

Identified main error sources in complex interferometry

Provided a method to estimate error bars for plasma parameters

Demonstrated the approach with real experimental data

Abstract

Expanding laser plasmas, produced by high energy laser radiation, possess both high thermal and magnetic field energy density. Characterization of such plasma is challenging but needed for understanding of its physical behaviour. Among all standard experimental techniques for plasma diagnostics, classical interferometry is one of the most convenient, informative and accurate. Attempts to extract more information from each single laser shot have led to development of complex interferometry, which under certain processing allows to reconstruct both plasma electron density and magnetic field strength distributions using just one data object. However, the increase in complexity and universality of the diagnostics requires a more detailed analysis of the extracted values and their accuracy.This work focuses on axisymmetric interaction geometry. We present general analysis, starting from the basic principles and trace main error sources, finally ending up with plasma density and magnetic field distributions with the derived error bars. Use of synthetic profiles makes the analysis universal, though we present an example with real experimental data in the Appendix.