A state-selected beam of hydroxyl radicals is generated using a pulsed discharge source and hexapole field. The OH radicals are characterized by resonance-enhanced multiphoton ionization (REMPI) spectroscopy via the nested D and 3 Rydberg states. Simplified spectra are observed from the selected ∣MJ∣ = 3/2 component of the upper Λ-doublet level of the lowest rotational state (J = 3/2) in ground (v″ = 0) and excited(v″ = 1–3) vibrational levels of the OH X state. Two-photon transitions are observed to the D (v′ = 0–3) and 3 (v′ = 0,1) vibronic levels, extending previous studies to higher vibrational levels of the Rydberg states. Spectroscopic constants are derived for the Rydberg states and compared with prior experimental studies. Complementary first-principle theoretical studies of the D and 3 Rydberg states [see M. P. J. van der Loo and G. C. Groenenboom, J. Chem. Phys. 123, 074310 (2005), following paper ] are used to interpret the experimental findings and examine the utility of the (2+1) REMPI scheme for sensitive detection of OH radicals.
Journal of Chemical Physics
AMERICAN INSTITUTE OF PHYSICS
Digital Object Identifier (DOI)
M. E. Greenslade, M. I. Lester, D. Č. Radenović, A. J. A. van Roij, D. H. Parker, “(2+1) Resonance Enhanced Ionization Spectroscopy of a State Selected Beam of OH Radicals,” J. Chem. Phys. 123, 074309 (2005)
© 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. J. Chem. Phys. 123, 074309 (2005)