Three-photon resonance ionization of atomic Mn in a hot-cavity laser ion source using Ti:sapphire lasers

Journal Article · Fri May 08 04:00:00 EDT 2015 · Journal of Physics. B, Atomic, Molecular and Optical Physics

DOI:https://doi.org/10.1088/0953-4075/48/11/115006· OSTI ID:1286764

Liu, Y. ^[1]; Gottwald, T. ^[2]; Mattolat, C. ^[2]; Wendt, K. ^[2]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Physics Division
2. Johannes Gutenberg Univ., Mainz (Germany). Inst. fur Physik

Three-photon resonance ionization of atomic manganese (Mn) in a hot-cavity ion source using Ti:sapphire lasers has been demonstrated. Three-step ionization schemes employing different intermediate levels and Rydberg or autoionizing (AI) states in the final ionization step are established. Strong AI resonances were observed via the 3d⁵4s5s f⁶S_5/2 level at 49 415.35 cm^-1, while Rydberg transitions were reached from the 3d⁵4s4d e ⁶D_9/2,7/2,5/2 levels at around 47 210 cm^-1. Analyses of the strong Rydberg transitions associated with the 3d⁵4s4d e ⁶D_7/2 lower level indicate that they belong to the dipole-allowed 4d→nf ⁶F° _9/2,7/2,5/2 series converging to the 3d⁵4s ⁷S₃ ground state of Mn II. From this series, an ionization potential of 59 959.56 ± 0.01 cm^-1 is obtained for Mn. At high ion source temperatures the semi-forbidden 4d→nf ⁸F° _9/2,7/2,5/2 series was also observed. The overall ionization efficiency for Mn has been measured to be about 0.9% when using the strong AI transition in the third excitation step and 0.3% when employing an intense Rydberg transition. Ultimately, our experimental data indicate that the ionization efficiency was limited by the interaction of Mn atoms with ion source materials at high temperatures.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1286764
• Journal Information: Journal of Physics. B, Atomic, Molecular and Optical Physics, Journal Name: Journal of Physics. B, Atomic, Molecular and Optical Physics Journal Issue: 11 Vol. 48; ISSN 0953-4075
• Publisher: IOP Publishing
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
Ti:sapphire laser
hot cavity
laser ion source
manganese
resonant laser ionization