Multiple ionization under strong XUV to X-ray radiation

Abstract

Abstract. We review the main aspects of multiple photoionization processes in atoms exposed to intense, short wavelength radiation. The main focus is the theoretical framework for the description of such processes as well as the conditions under which direct multiphoton multiple ionization processes can dominate over the sequential ones. We discuss in detail the mechanisms available in different wavelength ranges from the infrared to the hard X-rays. The effect of field fluctuations, present at this stage in all SASE free-electron-laser (FEL) facilities, as well as the effect of the interaction volume integration, are also discussed.

Time-dependent density-functional theory of strong-field ionization of atoms by soft x rays

“…As LOPT has shown itself to be in excellent agreement with experiment [8][9][10][11], we deduce that our TDDFT results have a tendency to slightly underestimate the total ionic yield. It must be added, however, that these differences are minor and are likely to fall within the present experimental accuracy of many FEL experiments.…”

“…On the other hand, short wavelength FEL radiation, more often than not, produces highly charged ions in abundance [5][6][7][8][9]13]. Typically, the stripping begins with the ejection of one * alisonc1986@gmail.com † Present address: Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, D-22761 Hamburg, Germany.…”

A perspective on high photon flux nonclassical light and applications in nonlinear optics

“…The enhancement of the multiphoton transition rates was also studied theoretically and observed experimentally in the XUV spectral region, using FEL sources [62] , whereas the differences compared with the laser-driven coherent XUV sources have been discussed in Ref. [63].…”

Multiple ionization of neon under soft x-rays: theory versus experiment

“…The formalism rests on a set of rate equations governing the production and depletion of the ionic yields during the pulse. For the photon energy, range of intensities and pulse duration employed in the experiment, the rate equations are perfectly valid (e.g., see discussion in [1,6,7]). The distribution of the laser intensity within the interaction volume, as determined by the focusing geometry of the laser beam, has been taken into account.…”