Considering the weakly relativistic correction to the Schroedinger equation, we have numerically investigated the dynamics and radiation of multiple charged ions in moderately intense (1016-1017 W/cm2) laser fields [1]. For this intensity regime, the magnetic effect of the laser field starts to become nonnegligible. The magnetic field pushes the electron wave packet along the laser propagation direction, especially in the vicinity of the nucleus when high electron velocities occur. Consequently a reduction of the expectation value of the electron wave packet is notable around the ionic core which may be connected with hollow ions. More dramatically the spin signatures of electrons can be exhibited even for moderate intensities, as well as relativistic corrections to the Stark shift of energy levels of intense laser -driven ions. Finally coherent X-ray generation is found to be feasible.
[1] S.X. Hu, C. H. Keitel, Europhys. Lett. 47, 318 (1999); S. X. Hu, C. H. Keitel, Phys. Rev. Lett. 83, 4709 (1999).