Characterization of spin–orbit autoionizing Rydberg states excited via one-photon absorption from the F 1Δ2 Rydberg state of HBr

Abstract

Characterization of spin-orbit autoionizing Rydberg states excited via one-photon absorption from the F 1D2 Rydberg state of HBr. Wales, N.P.L.; Buma, W.J.; de Lange, C.A.; Lefebvre-Brion, H. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Rotationally and parity resolved excitation spectra of autoionizing Rydberg states of HBr in the energy region between the 2 ⌸ 3/2 and 2 ⌸ 1/2 ionic thresholds have been obtained in a double resonant excitation scheme via single rotational levels of the vibrationless F 1 ⌬ 2 Rydberg state. A cursory examination of these spectra reveals the presence of s, p, d, and f Rydberg series. Apart from the f series, which show almost Hund's case ͑e͒ coupling, these series clearly exhibit an angular momentum coupling scheme intermediate between Hund's case ͑c͒ and ͑e͒. As a result it is difficult to assign them as converging upon specific ionic rotational thresholds. A detailed analysis of the excitation spectra has consequently been performed employing multichannel quantum defect theory calculations, allowing for a determination of the quantum defects of the Hund's case ͑a͒ basis states and the relevant transition moments, and, concurrently, the assignment of nearly all the observed autoionizing resonances.

Photoelectron imaging following 2 + 1 multiphoton excitation of HBr

“…40 As a result of the large spin-orbit coupling constant of the X 2 P state of HBr 1 , the respective Rydberg states can be understood as mixtures of singlet and triplet configurations. 41,42 Since for Rydberg states it can be assumed that the ionization transition moments for singlet and triplet states are nearly equal, a complete singlettriplet mixing should result in an ionization process in which the electronic configuration of the ionic core is preserved. 43 Conversely, one can use the HBr 1 ( 2 P 1/2 ) : HBr 1 ( 2 P 3/2 ) branching ratio to determine the extent of singlet-triplet mixing.…”

Zero kinetic energy-pulsed field ionization and resonance enhanced multiphoton ionization photoelectron spectroscopy: Ionization dynamics of Rydberg states in HBr

“…Moreover, in a number of cases resonances were even missing where, on the basis of the presence of neighboring resonances, they would have been expected to be present. These observations can be rationalized when we realize that the resonances that we see in fact derive from very low-n Rydberg states converging upon 33 We therefore conclude that spin-orbit autoionization still may play an important role in HBr. Such a conclusion is in line with our observation that the ZEKE-PFI signals via the F 1 ⌬ 2 state in the region of the 2 ⌸ 1/2 limit are considerably less intense than those obtained after excitation of the f 3 ⌬ 2 state in the region of the 2 ⌸ 3/2 limit.…”

Two-photon resonance enhanced multiphoton ionization photoelectron spectroscopy of the SH (SD) radical below and above the lowest ionization threshold

“…Only a few examples of photoionization spectra are known in which autoionization, in particular spin-orbit autoionization, proceeds on a sufficiently slow time scale to allow for rotational resolution. 34,[58][59][60][61][62] The linewidths and line shapes for such autoionizing Rydberg states are then clearly determined by the rate of autoionization. In the present study the lines of our Rydberg states have essentially the same widths as the lines of the Rydberg states discussed in the previous sections.…”