Resonance-enhanced multiphoton-ionization photoelectron spectroscopy of even-parity autoionizing Rydberg states of atomic sulphur

Abstract

Several previously unobserved Rydberg states of the sulphur atom above the lowest ionization threshold are identified and assigned using (2ϩ1) resonance-enhanced multiphoton-ionization photoelectron spectroscopy. All states were accessed by two-photon transitions from either the 3 P ground or the 1 D excited state, prepared by in situ photodissociation of H 2 S. The observed states derive from the ( 2 D o )5p and ( 2 P o )4p configurations. For the ( 2 D o )5p 3 F and ( 2 P o )4p 3 D triplets, extensive photoelectron spectroscopic studies enable a detailed comparison of the autoionization and photoionization rates of these states.

Measurement of the partial photoionization cross sections and asymmetry parameters of S atoms in the photon energy range 10.0–30.0eV using constant-ionic-state spectroscopy

“…1 Of the previous experimental work, the most relevant to this present paper is the investigation of Gibson et al, 13 who studied the photoionization spectrum of atomic sulfur using photoionization mass spectrometry from the ionization threshold, 10.35 eV, to 13.40 eV, and the work of Tondello, 14 who measured and analyzed the absorption spectrum of S from 6.77 to 13.77 eV. Also, Woutersen et al 15,16 investigated sulfur atoms with ͑2+1͒ resonanceenhanced multiphoton ionization spectroscopy and observed even-parity Rydberg states, allowed by two-photon excitation from the ground state, with S + 2 D and 2 P ionic cores above the lowest ionization threshold. The most relevant theoretical work is that of Dill et al, 17 who obtained photoelectron ␤ parameters for the ͑3p͒ −1 S + ͑ 4 S , 2 D , 2 P͒ ← S͑ 3 P͒ ionizations in the photon energy region 10.0-65.0 eV using Hartree-Fock calculations with explicit expressions for the angular distribution of photoelectrons produced by electric dipole ionization of closed and open shell atoms.…”

Two-photon Doppler-free ultraviolet laser spectroscopy on sulphur atoms

“…The connection with even parity excited states is studied through visible and infrared spectroscopy involving transitions between excited states [5][6][7][8]. In addition, direct measurements of transitions between even parity states are studied through 2 + 1 resonance enhanced multiphoton ionization (REMPI) spectroscopy [9,10].…”

Two-photon Doppler-free ultraviolet laser spectroscopy on sulphur atoms

“…The connection with even parity excited states is studied through visible and infrared spectroscopy involving transition between excited states [5][6][7][8]. In addition, direct measurements of transitions between even parity states are studied through 2+1 resonance enhanced multiphoton ionization (REMPI) spectroscopy [9,10].…”