Abstract
Resonant spectra of highly charged ions are evaluated numerically in the presence of super intense high-frequency laser pulses up to 1022W/cm2. The associated field strengths are still small compared to those inherent in highly charged ions, restricting us to the relativistic multiphoton regime. We predict the emission of hard X-ray radiation due to near-resonant multiphoton interaction with clear relativistic signatures for the one-electron ions Xe53+ and U91+.