## Files in this item

FilesDescriptionFormat

application/vnd.openxmlformats-officedocument.presentationml.presentation

1163757.pptx (37MB)
PresentationMicrosoft PowerPoint 2007

application/pdf

3171.pdf (21kB)
AbstractPDF

## Description

 Title: PRECISION RAMSEY-COMB SPECTROSCOPY OF MOLECULAR HYDROGEN IN THE DEEP-UV Author(s): Eikema, K.S.E. Contributor(s): Ubachs, Wim; Salumbides, Edcel John; Krauth, J.; Favier, M.G.J.; Roth, C.; Altmann, R.K.; Dreissen, L.S. Subject(s): Mini-symposium: Frequency-Comb Spectroscopy Abstract: High-precision spectroscopy experiments with simple atomic and molecular systems provide important benchmarks for tests of bound-state Quantum Electrodynamics (QED). In recent years there has been significant progress in both experiment [1,2] and theory [3] for QED tests in H$_{2}$. Even investigations of the proton radius puzzle [4] might become feasible in this molecule if the dissociation energy can be determined at a level of 10 kHz [3]. For this latter target, we developed an excitation method, Ramsey-comb spectroscopy, that enables kHz-level precision spectroscopy in the deep-UV. The method is based on excitation with amplified and upconverted frequency comb laser pulses [5]. It has allowed us to measure the $EF^{1} \Sigma_{g}^{+} - X^{1} \Sigma_{g}^{+}(0,0)$ Q1 two-photon transition at 202 nm with an accuracy of 73 kHz [6]. This result is two orders of magnitude better than obtained with previous experiments, and combined with future improved measurements of the EF ionization energy, this could lead to a dissociation energy with an uncertainty below 100 kHz. New measurements from V=1 and N=0 are now in preparation. Moreover, a new setup has been constructed to extend Ramsey-comb spectroscopy to the vacuum- and extreme-ultraviolet spectral region through high-harmonic generation, and an experiment is in preparation to demonstrate this. \newline \newline [1] J. Liu et al., J. Chem. Phys. 130, 174306 (2009) \newline [2] W. Ubachs et al., J. Mol. Spectr. 320, 1-12 (2016) \newline [3] M. Puchalski et al., Phys. Rev. A 95, 052506 (2017) \newline [4] R. Pohl et al., Science 353, 669 (2016) \newline [5] J. Morgenweg et al., Nature Physics 10, 30-33 (2014) \newline [6] R.K. Altmann et al., Phys. Rev. Lett. 120, 043204 (2018) \newline Issue Date: 06/18/18 Publisher: International Symposium on Molecular Spectroscopy Citation Info: APS Genre: Conference Paper / Presentation Type: Text Language: English URI: http://hdl.handle.net/2142/100583 DOI: 10.15278/isms.2018.MG01 Other Identifier(s): MG01 Date Available in IDEALS: 2018-08-172018-12-12
﻿