Impact of coherence in radiation from ultrahigh-field atomic ionization

摘要

We quantify interference effects on radiation by calculating the angle- and energy-resolved Larmor radiation from atomic ionization in the focus of ultraintense field. Our calculations use a Monte Carlo classical and semiclassical tunneling probability current models of ionization for intensities in the range of 10(16) to 10(20) W/cm(2). For nonrelativistic intensities, whether the radiation from the photoionization is treated coherently or incoherently, classically or semiclassically, leads to a negligible effect on radiation. For relativistic intensities, coherently summing across the tunneling ionization probability current decreases the radiation by an order of magnitude when compared to classical ionization or incoherent summation of the radiation from the tunneling ionization probability current. The interference effect is most pronounced for high-energy photons since ionization and the electron quiver may be 1 mu m and extends over multiple radiation wavelengths.