ELECTRIC-FIELD EFFECTS ON THE PHOTODETACHMENT OF H- BELOW THE N=3 THRESHOLD

We have implemented an L(2) integrable method with B-spline Oasis whic h allows us to calculate photodetachment cross sections of the H- ion in the presence of a constant electric field. The behaviour of the Fes hbach resonances lying below the N = 2 and N = 3 thresholds is analyse d in detail. Further insight on the relative importance of autoionizat ion and tunnelling is provided by using a stabilization procedure. Our results permit us to explain most of the experimental findings and sh ow the existence of resonance structures previously unobserved.