Darmstadt 2008 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
A: Fachverband Atomphysik
A 20: Experiments with FLASH and FEL perspectives: an overview
A 20.3: Talk
Thursday, March 13, 2008, 11:45–12:00, 3C
Atoms in the focus of an extreme-ultraviolet laser — •Mathias Richter1, Andrei A. Sorokin1,2, Kai Tiedtke3, and Hubertus Wabnitz3 — 1Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, 10587 Berlin, Germany — 2Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, 194021 St. Petersburg, Russia — 3Deutsches Elektronen-Synchrotron, Notkestraße 85, 22603 Hamburg, Germany
First investigations at the new Free-electron LASer in Hamburg FLASH [1] on rare gases have shown that multiphoton ionization at photon energies above ionization thresholds is dominated by sequential processes via ionic states [2]. However, in a recent work on xenon atoms, irradiance levels of more than 1000 terawatt per square centimeter were achieved at a photon energy of 93 electron volts by microfocusing of the FLASH beam with the aid of a spherical extreme-ultraviolet multilayer mirror [3]. Although these experiments were performed within the regime of the classical photoelectric effect, explanation of the unexpected high degrees of photoionization observed seems to be beyond the scope of the perturbation theory and photons as the light particles. As an extension of this study, we present and discuss, here, also new results on the generation of Li-like neon under similar conditions.
[1] W. Ackermann et al., Nature Photonics 1, 336 (2007)
[2] A. A. Sorokin et al., Phys. Rev. A 75, 051402(R) (2007)
[3] A. A. Sorokin et al., Phys. Rev. Lett. 99, 213002 (2007)