Abstract
The interaction of intense vacuum-ultraviolet radiation from a free-electron laser with rare gas atoms is investigated. The ionization products of xenon and argon atomic beams are analyzed with time-of-flight mass spectroscopy. At 98 nm wavelength and multiple charged ions up to () are detected. From the intensity dependence of multiple charged ion yields the mechanisms of multiphoton processes were derived. In the range of the ionization is attributed to sequential multiphoton processes. The production of multiple charged ions saturates at 5–30 times lower power densities than at 193 and 564 nm wavelength, respectively.
- Received 29 January 2004
DOI:https://doi.org/10.1103/PhysRevLett.94.023001
©2005 American Physical Society