Rotational autoionization and energy levels of triplet nf, v=0 Rydberg states of H{sub 2}
- Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States)
We have measured the energy levels and purely rotational autoionization rates of 25 different triplet Rydberg states of the H{sub 2} molecule with quantum numbers n=14{endash}29, L=3, v=0, and R=2{endash}4. Electron impact excites the ground-state molecules in a beam to the metastable c(2p){sup 3}{Pi}{sub u} states. Two-color laser excitation from two counterpropagating single-mode cw dye laser beams excites the metastable molecules through an intermediate (3d){sup 3}{Sigma} or (3d){sup 3}{Pi} state to the triplet nf Rydberg states. The linewidths of the transitions to the Rydberg states give the autoionization rates, which vary widely and agree satisfactorily with the quadrupole-moment-polarizability long-range Coulomb interaction model. The laser transitions have been measured to 0.002 cm{sup {minus}1}. We use these measurements, the model, and an extrapolation of the Rydberg series to derive the ionization potential of the metastable c(2p){sup 3}{Pi}{sub u} v=0 states with an accuracy of 0.020 cm{sup {minus}1} and the energy difference between the singlet ground state and the triplet metastable c(2p){sup 3}{Pi}{sub u} states with an accuracy of 0.025 cm{sup {minus}1}. This allows the whole singlet and triplet manifolds of H{sub 2} to be linked together with higher accuracy: our correction to Dieke{close_quote}s H{sub 2} triplet term values is {minus}149.704(25) cm{sup {minus}1}. {copyright} {ital 1997} {ital The American Physical Society}
- OSTI ID:
- 450313
- Journal Information:
- Physical Review A, Journal Name: Physical Review A Journal Issue: 2 Vol. 55; ISSN 1050-2947; ISSN PLRAAN
- Country of Publication:
- United States
- Language:
- English
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