Control of the K-shell electron dynamics in atomic beryllium with intense chirped X-ray laser pulses

The advent of X-ray free-electron lasers opens new opportunities to explore inner-shell electron dynamics in atoms. In this work, we present a numerical investigation of the two-photon double K-shell ionization of atomic beryllium driven by intense chirped X-ray laser pulses. Our theoretical approach is based on the direct resolution of the time-dependent Schrödinger equation using a configuration-type B-spline spectral method [1-4], including full core-core correlation in the initial state and throughout the laser-driven dynamics.

We probe the core electron dynamics over a broad range of X-ray photon energies and examine the effect of the sign and magnitude of the chirp on the ionization process.

We present the results of the core electron energy distributions across the direct, near-threshold and far sequential regimes. At high photon energy and strong chirp, we observe a pronounced stretching of the sequential peaks, which we further analyze via Wigner time-frequency representations. This work represents the first theoretical study demonstrating the possibility to probe and control the electron dynamics in an atomic K-shell using intense chirped X-ray laser pulses.

 

[1] S. Laulan, M.-A. Albert, S. Barmaki, J. Electron Spectrosc. Relat. Phenom. 271, 147429 (2024)

[2] S. Barmaki, M.-A. Albert, S. Laulan, Chem. Phys. 517, 24 (2019)  

[3] S. Barmaki, M.-A. Albert, S. Laulan, J. Phys. B: At. Mol. Opt. Phys. 51, 105002 (2018)  

[4] S. Barmaki, P. Lanteigne, S. Laulan, Phys. Rev A 89, 063406 (2014)