Determination of rovibrational intervals in H2+ with sub-MHz accuracy

Hoelsch, Nicolas

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https://hdl.handle.net/2142/100636 Copy

Description

Title

Determination of rovibrational intervals in H2+ with sub-MHz accuracy

Author(s)

Hoelsch, Nicolas

Contributor(s)

• Jungen, Christian
• Merkt, Frederic
• Beyer, Maximilian

Issue Date

2018-06-18

Keyword(s)

Mini-symposium: Frequency-Comb Spectroscopy

Abstract

H + 2 is the simplest of all molecules and as such an important system for the development of molecular quantum mechanics. The rovibrational energy-level structure of this one-electron system can be calculated extremely precisely by quantum-chemical methodsa . By comparison with the results of precise spectroscopic measurements of rovibrational intervals, fundamental constants or particle properties, such as the proton-to-electron mass ratio or the proton size, can be determinedb . Because the rotational and vibrational transitions of H+ 2 are electric-dipole forbidden, the experimental data on its energy-level structure are limited. We present the determination of spin-rovibrational intervals in H+ 2 from high-resolution measurements of the Rydberg spectrum of H2 and Rydberg-series extrapolation using multichannel quantum defect theoryc . Choosing suitable doublewell valence states of H2, characterized by long lifetimes and favorable Franck-Condon factors to different vibrational states in the ion, allows us to excite Rydberg states that converge on selected rovibrational levels of H+ 2 . For the excitation of Rydberg states, a resonant three-photon excitation scheme was employed, using pulsed VUV and VIS laser sources to reach the intermediate valence state and a continuous-wave (cw) near-infrared laser source for the excitation to the Rydberg states. The valence state - Rydberg state intervals could be measured with a relative accuracy of 3E-10 using an optical frequency comb for the frequency calibration of the cw laser and minimizing systematic uncertainties.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100636

DOI

10.15278/isms.2018.MG04

Copyright and License Information

Copyright 2018 Nicolas Hoelsch

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