Critical Test of Simulations of Charge-Exchange-Induced X-Ray Emission in the Solar System

TL;DR

This study critically tests charge-exchange models for X-ray emission in the solar system by comparing experimental spectra with new classical trajectory Monte Carlo calculations, revealing potential inaccuracies in current modeling approaches.

Contribution

It provides the first detailed comparison between experimental charge-exchange X-ray spectra and advanced theoretical models at the quantum orbital level.

Findings

Classical trajectory Monte Carlo calculations align well with experimental spectra.

Current CX models may lead to erroneous interpretations of X-ray emissions.

Experimental techniques effectively isolate primary charge-exchange reactions.

Abstract

Experimental and theoretical state-selective X-ray spectra resulting from single-electron capture in charge exchange (CX) collisions of Ne^10+ with He, Ne, and Ar are presented for a collision velocity of 933 km s^-1 (4.54 keV nucleon^-1), comparable to the highest velocity components of the fast solar wind. The experimental spectra were obtained by detecting scattered projectiles, target recoil ions, and X-rays in coincidence; with simultaneous determination of the recoil ion momenta. Use and interpretation of these spectra are free from the complications of non-coincident total X-ray measurements that do not differentiate between the primary reaction channels. The spectra offer the opportunity to test critically the ability of CX theories to describe such interactions at the quantum orbital angular momentum level of the final projectile ion. To this end, new classical trajectory Monte Carlo calculations are compared here with the measurements. The current work demonstrates that modeling of cometary, heliospheric, planetary, and laboratory X-ray emission based on approximate state-selective CX models may result in erroneous conclusions and deductions of relevant parameters.