ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The (X 2Σ+g)np Rydberg states converging to the X 2Σ+g, v+≥9 ionization thresholds of molecular hydrogen were excited by double-resonance excitation via the E,F 1Σ+g, v = 6 level. The energy region of interest (139 500–140 000 cm−1) included the X 2Σ+g, v+=9, N+=0–3 ionization thresholds as well as the energetic threshold for ion pair formation. The decay of the autoionizing Rydberg states was studied by both conventional and constant-ionic-state photoelectron spectrometry. The results support the Δv=minimum propensity rule for vibrational autoionization of Rydberg states with a high level of vibrational excitation. However, the relative intensities of the (X 2Σ+g)np, v'≥ 9 Rydberg series converging to different rotational levels of the ion are dramatically different from those for the analogous Rydberg series with v'≤2. In addition, the two-color photoelectron spectrum via the E,F 1Σg+, v=6 level shows considerable intensity in the v+=7 and 8 photoelectron bands both on and off resonance, in marked contrast with the single-color photoelectron spectrum obtained for the same intermediate levels. These observations may be due to the dependence of the transition dipole matrix elements on the internuclear distance and to the presence of doubly excited electronic states that cross the H2+ X 2Σ+g potential curve at a total energy close to that accessed by the two-color excitation scheme.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.463045
