<i>XMDYN</i>and<i>XATOM</i>: versatile simulation tools for quantitative modeling of X-ray free-electron laser induced dynamics of matter

TLDR

X‑ray free‑electron lasers have rapidly advanced, enabling studies in warm dense matter and coherent imaging, and a single pulse can trigger complex core‑hole–induced dynamics in matter. The authors aim to present and detail the XMDYN and XATOM tools for modeling excitation and relaxation dynamics of matter under XFEL irradiation. XMDYN simulates high‑intensity X‑ray–induced matter dynamics using atomic data computed by the ab initio XATOM toolkit.

Abstract

Rapid development of X-ray free-electron laser (XFEL) science has taken place in recent years owing to the consecutive launch of large-scale XFEL instruments around the world. Research areas such as warm dense matter physics and coherent X-ray imaging take advantage of the unprecedentedly high intensities of XFELs. A single XFEL pulse can induce very complex dynamics within matter initiated by core-hole photoionization. Owing to this complexity, theoretical modeling revealing details of the excitation and relaxation of irradiated matter is important for the correct interpretation of the measurements and for proposing new experiments. XMDYN is a computer simulation tool developed for modeling dynamics of matter induced by high-intensity X-rays. It utilizes atomic data calculated by the ab initio XATOM toolkit. Here these tools are discussed in detail.