Alignment of OCS, CS_{2}, and I_{2} molecules embedded in helium nanodroplets is measured as a function of time following rotational excitation by a nonresonant, comparatively weak ps laser pulse. The distinct peaks in the power spectra, obtained by Fourier analysis, are used to determine the rotational, B, and centrifugal distortion, D, constants. For OCS, B and D match the values known from IR spectroscopy. For CS_{2} and I_{2}, they are the first experimental results reported. The alignment dynamics calculated from the gas-phase rotational Schrödinger equation, using the experimental in-droplet B and D values, agree in detail with the measurement for all three molecules. The rotational spectroscopy technique for molecules in helium droplets introduced here should apply to a range of molecules and complexes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.125.013001 | DOI Listing |
J Phys Chem A
January 2025
Univ Rennes, CNRS, IPR (Institut de Physique de Rennes)─UMR 6251, F-35000 Rennes, France.
Chloronium (HCl) is an important intermediate of Cl-chemistry in space. The accurate knowledge of its collisional properties allows a better interpretation of the corresponding observations in interstellar clouds and, therefore, a better estimation of its abundance in these environments. While the ro-vibrational spectroscopy of HCl is well-known, the studies of its collisional excitation are rather limited and these are available for the interaction with helium atoms only.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, China.
Partial wave analysis is key to interpretation of the photoionization of atoms and molecules on the attosecond timescale. Here we propose a heterodyne analysis approach, based on the delay-resolved anisotropy parameters to reveal the role played by high-order partial waves during photoionization. This extends the Reconstruction of Attosecond Beating By Interference of Two-photon Transitions technique into the few-photon regime.
View Article and Find Full Text PDFACS Earth Space Chem
December 2024
School of Chemistry, The University of Edinburgh, Joseph Black Building, David Brewster Road, King's Buildings, Edinburgh EH9 3FJ, Scotland, U.K.
Identification of the molecular carriers of diffuse interstellar bands (DIBs) requires gas phase electronic spectra of suitable candidate structures. Recording the spectra of these in the laboratory is challenging because they include large, carbon-rich molecules, many of which are likely to be ionic. The electronic spectra of ions are often obtained using action spectroscopy methods, which can induce small perturbations to the absorption characteristics and hinder comparison with astronomical observations.
View Article and Find Full Text PDFCommun Phys
December 2024
LaserLaB, Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, the Netherlands.
Laser spectroscopy of atomic hydrogen and hydrogen-like atoms is a powerful tool for tests of fundamental physics. The 1-2 transition of hydrogen in particular is a cornerstone for stringent Quantum Electrodynamics (QED) tests and for an accurate determination of the Rydberg constant. We report laser excitation of the 1-2 transition in singly-ionized helium (He), a hydrogen-like ion with much higher sensitivity to QED than hydrogen itself.
View Article and Find Full Text PDFAnal Chem
December 2024
MOBILion Systems, Inc., 4 Hillman Drive, Suite 130, Chadds Ford, Pennsylvania 19317, United States.
Various rounded turn designs in Structures for Lossless Ion Manipulation (SLIM) were explored via ion trajectory simulations. The optimized design was integrated into a SLIM ion mobility (IM) system coupled with a time-of-flight (TOF) mass spectrometer (MS) for further experimental investigation. The SLIM-TOF IM-MS system was assessed for IM resolution and ion transmission efficiency across a wide / range using various RF frequencies and buffer gas combinations.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!