Observation of laser-assisted Auger decay in argon.

The effect of an intense laser field on the energies of Auger electrons has been investigated using electron spectroscopy. A laser-generated gallium plasma pumped by a subpicosecond laser yields pulsed broadband x radiation, used to induce $\mathrm{LMM}$ Auger transitions in argon. The intense dressing beam (($\ensuremath{\lambda}=800$ nm) causes the appearance of up to four sidebands on both sides of the original Auger lines. Recording the magnitude of the sidebands versus the time delay between the dressing and x-ray pulses shows that our source delivers subpicosecond pulses in the 250-400 eV range.