TOWARD UNDERSTANDING THE ROLE OF STARK EFFECTS WHEN PROBING THE NUCLEAR HYPERFINE STATES OF ATOMIC-HYDROGEN

A variation on velocity-aligned Doppler spectroscopy is used to probe the nuclear hyperfine states of atomic hydrogen resulting from the 193 nm photodissociation of HBr. By utilizing 1 + 1 resonance-enhanced io nization through the Lyman-alpha transition along with a novel experim ental approach, one can observe the onset of Stark effects that come a bout because of the modest electric field present in the ionization re gion of the mass spectrometer. A straightforward theoretical treatment is used to address the observed behavior.