Relativistic ionization characteristics of laser-driven hydrogenlike ions

In this contribution, we investigate the relativistic ionization characteristics of highly charged hydrogenlike ions in short intense laser pulses as a function of the laser pulse parameters by means of the numerical solution of the time-dependent Dirac equation and the time-dependent Klein-Gordon equation as well as by the classical phase-space averaging method. For this purpose, we generalize the phase-space averaging method such that it is applicable to relativistically driven particles in arbitrary central potentials. If the ionization probability is not too small, quantum mechanical and classical methods give similar results for laser wavelengths in the range from the near-infrared to soft x-ray radiation. We find that ionization in few-cycle intense laser pulses depends sensitively on the pulses' peak intensity but little on the pulse tails and on the pulse energy. The ionization probability is shown to be strongly linked to the peak intensity allowing for an estimation of the laser intensity via ionization yields.

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