SCALED-TIME DYNAMICS OF IONIZATION OF RYDBERG STARK STATES BY HALF-CYCLE PULSES

We study the time dependence of the ionization of Stark Rydberg states of hydrogen subject to half-cycle electromagnetic pulses. We find tha t the quantum ionization probability for the most 'blue-shifted' Stark state exhibits a purely classical oscillating pattern as a function o f time whose frequency is associated with the perturbed orbital freque ncy of the electron. We show that these oscillations could be observed experimentally when a scaled-time analysis of ionization data for hyd rogen is employed. Our calculations are compared with experimental dat a for sodium.