Diffraction of light by plasma in the solar system

TL;DR

This paper develops a wave-optical Mie theory to analyze how solar system plasma affects electromagnetic wave propagation, accounting for phase shifts and diffraction, with applications in high-precision astronomy.

Contribution

It introduces a comprehensive Mie theory for EM wave diffraction in solar plasma, incorporating a generic electron density model and eikonal approximation for accurate predictions.

Findings

Quantifies plasma-induced phase shifts on EM waves.

Provides a wave-optical framework for diffraction in solar plasma.

Applicable to high-precision astronomical measurements.

Abstract

We study the propagation of electromagnetic (EM) waves in the solar system and develop a Mie theory that accounts for the refractive properties of the free electron plasma in the extended solar corona. We use a generic model for the electron number density distribution and apply the eikonal approximation to find a solution in terms of Debye potentials, which is then used to determine the EM field both within the inner solar system and at large heliocentric distances. As expected, the solution for the EM wave propagating through the solar system is characterized by a plasma-induced phase shift and related change in the light ray's direction of propagation. Our approach quantitatively accounts for these effects, providing a wave-optical treatment for diffraction in the solar plasma. As such, it may be used in practical applications involving big apertures, large interferometric baselines or otherwise widely distributed high-precision astronomical instruments.