Ml=1 photoionization spectrum of hydrogen in strong dc electric fields

We present experimental and theoretical studies of the ml=1 photoionization channel of H(n=2,ml=0) blue and red parabolic states in strong external electric fields in the energy region between the classical ionization threshold at E=-2 F and the isolated-atom photoionization threshold at E=0. Our results indicate that the ionization from the rapidly ionizing channels is concentrated away from but between the two thresholds. We also find that the fractions of the nuclear charge Z1=0, (1/2, and 1 define two regions that classify the properties of the states. These results are in contrast to our previous results for the ml=0 channels where the ionization is concentrated at the two thresholds and the fractions Z1=0, (1/4, (1/2, (3/4, and 1 define four quarters that classify the properties of these channels.