Feasibility Study of Measuring Degree of Linear Polarization of the Solar F-Corona Using Filter Observations on the COronal Diagnostic EXperiment

Abstract

One of the most unrevealed pieces of information about solar F-corona is its polarization. We propose the possibility of measuring the degree of linear polarization ($D_{\mathrm{F}}$) of the F-corona along the radial distance from the Sun using the signal of two filters installed on the COronal Diagnostic EXperiment (CODEX), which will be mounted on board the International Space Station in December 2023. By analyzing the signal and noise of CODEX with Monte-Carlo simulations, we can derive $D_{\mathrm{F}}$ with a 1.4 nm-width narrow bandpass filter centered at 393.55 nm and a 10 nm-width broad bandpass filter centered at 393.5 nm by stacking six images and integrating over $1\,R_{\odot}\times1\,R_{\odot}$. The $D_{\mathrm{F}}$ measured by CODEX will help reduce the uncertainty of the K-coronal polarization ($pB_{\mathrm{K}}$), a main target of the mission, as well as to provide a better understanding of the F-corona.