Excitation of narrow x-ray transitions in thin-film cavities by focused pulses

TL;DR

This paper presents a semi-analytical method to compute the excitation of narrow x-ray transitions in thin-film cavities by focused pulses, enhancing understanding of pulse propagation in these structures.

Contribution

It introduces a novel semi-analytical algorithm for modeling x-ray pulse interactions with thin-film cavities, requiring minimal numerical computation.

Findings

The algorithm accurately models pulse propagation in cavity structures.

Focused x-ray pulses can effectively excite narrow transitions in thin films.

The method is validated against limiting cases and previous experimental setups.

Abstract

A method to compute the excitation of narrow transitions at hard x-ray energies by short focused x-ray pulses is developed. In particular, the effect of thin-film cavities on the pulse propagation is incorporated via a semi-analytical algorithm requiring the numerical evaluation of only one two-dimensional Fourier transform. We investigate various limiting cases to confirm the reliability of the algorithm. As an application, we show how a focused x-ray pulse propagates in cavity structures utilized in previous theoretical studies and experiments with collimated beams.