Spectroscopy of X-Ray-Boosted Photoionization with an Intense Laser Pulse

The present study shows that x-ray photoionization in the presence of an intense laser pulse has interesting energetic and statistical properties due to field modulation and interference between photoelectrons. The spectral cut-off energies, integral, and double integral reflect the strength, time, and interference of the laser field modulation. New methods are proposed for precise intense-laser-pulse measurement in situ. These methods have the advantages of accuracy, simplicity, speed, and large dynamic ranges.