Abstract

Previous microwave ionization experiments with hydrogen atoms have used fast atomic beams containing atoms in a distribution of quantum states.^1,2 Yet it is difficult to carry out reliable quantal numerical calculations of the ionization probability without using a one-dimensional model.^3,4 We have completed a detailed investigation of the ionization probability in which we used an added static electric field to achieve an almost one-dimensional atom–field system.^5,6 Here we report results for the peak field strength for 10% ionization probability and for ratios of the microwave frequency to initial Kepler electron orbit frequency in the range 0.6 to 1.2. Atoms having initial principal quantum numbers 60, 65, 69, and 72 were each used to obtain a portion of the data; the cutoff quantum number above which an atom was considered ionized was 90. The static field strength was 8.0 V/cm.

© 1993 Optical Society of America