English
Related papers

Related papers: Time-resolving the UV-initiated photodissociation …

200 papers

Photodissociation by ultraviolet radiation is the key destruction pathway for CS in photon-dominated regions, such as diffuse clouds. However, the large uncertainties of photodissociation cross sections and rates of CS, resulting from a…

Astrophysics of Galaxies · Physics 2019-09-11 Zhongxing Xu , Nan Luo , S. R. Federman , William M. Jackson , Cheuk-Yiu Ng , Lee-Ping Wang , Kyle N. Crabtree

Photoelectron-photoion coincidence momentum imaging has been performed to investigate excitation processes on dissociative ionization of OCS, OCS $\to$ OCS$^+$ + e$^-$ $\to$ OC + S$^+$ + e$^-$, in phase-locked $\omega + 2\omega$ intense…

Atomic Physics · Physics 2026-02-18 Tomoyuki Endo , Tomohito Otobe , Ryuji Itakura

Non Born-Oppenheimer quantum dynamics of H$_{2}^{+}$ excited by shaped one-cycle laser pulses linearly polarized along the molecular axis have been studied by the numerical solution of the time-dependent Schr\"odinger equation within a…

Atomic and Molecular Clusters · Physics 2017-08-02 Guennaddi K. Paramonov , Oliver Kühn , Andre D. Bandrauk

We study the dissociation of H$_2$$^+$ in uv laser pulses by solving the non-Born-Oppenheimer time-dependent Schr\"{o}dinger equation as a function of the photon energy $\omega$ of the pulse. Significant enhancements of the dissociation…

Atomic and Molecular Clusters · Physics 2014-07-22 Kunlong Liu , Qianguang Li , Pengfei Lan , Peixiang Lu

Accurate photodissociation cross sections have been computed for transitions from the X $^1\Sigma^+$ ground electronic state of CS to six low-lying excited electronic states. New ab initio potential curves and transition dipole moment…

We report a study of the electronic and nuclear relaxation dynamics of the photoexcited RNA base uracil in the gas phase, using time-resolved core level photoelectron spectroscopy together with high level calculations. The dynamics was…

Molecular iodine was photoexcited by a strong 800 nm laser, driving several channels of multiphoton excitation. The motion following photoexcitation was probed using time-resolved X-ray scattering, which produces a scattering map…

Chemical Physics · Physics 2020-03-25 Philip H. Bucksbaum , Matthew R. Ware , Adi Natan , James P. Cryan , James M. Glownia

The electronic and nuclear dynamics in methanol, following 156~nm photoexcitation, are investigated by combining a detailed analysis of time-resolved photoelectron spectroscopy experiments with electronic structure calculations. The…

We use transient absorption spectroscopy to monitor the ionization and dissociation products following two-photon excitation of pure liquid water. The two decay mechanisms occur with similar yield for an excitation energy of 9.3 eV, whereas…

Chemical Physics · Physics 2009-11-13 Christopher G. Elles , Ilya A. Shkrob , Robert A. Crowell , Stephen E. Bradforth

The photodissociation dynamics of N$_3^+$ excited from its $^3 \Sigma_{\rm g}^{-}$ ground to the first excited singlet and triplet states is investigated. Three dimensional potential energy surfaces for the $^1$A$'$, $^1$A$''$, and $^3$A$'$…

The photodissociation cross-section of SrCl$^+$ is measured in the spectral range of 36000 -- 46000 cm$^{-1}$ using a modular time-of-flight mass spectrometer (TOF-MS). By irradiating a sample of trapped SrCl$^+$ molecular ions with a…

In this work we investigate the relaxation processes of 2-thiouracil after UV photoexcitation to the S2 state through the use of ultrafast, single-color, pump-probe UV/UV spectroscopy. We place focus on investigating the appearance and…

Chemical Physics · Physics 2022-09-01 Matthew S. Robinson , Mario Niebuhr , Markus Gühr

Water is an important molecule in interstellar and circumstellar environments. Previous observations of mid-infrared rotational lines of OH suggest that these lines may be used to probe the photodissociation of water. In this work, cross…

Astrophysics of Galaxies · Physics 2021-06-30 Benoît Tabone , Marc C. van Hemert , Ewine F. van Dishoeck , John H. Black

Time-resolved x-ray scattering (TRXS) measures internuclear separations in a molecule following laser-induced photoexcitation. The molecular dynamics induced by the excitation laser may lie on one or several bound or dissociative electronic…

Atomic Physics · Physics 2019-09-25 MR Ware , JM Glownia , N Al-Sayyad , JT O'Neal , PH Bucksbaum

Ultraviolet irradiation of ice is of great interest for understanding the chemistry in both atmospheric and astrophysical environments. In interstellar space, photodissociation of H2O molecules can be a driving force behind the chemistry on…

Astrophysics · Physics 2016-08-30 Stefan Andersson , Geert-Jan Kroes , Ewine F. van Dishoeck

Soft X-rays (90-173 eV) from the 3rd generation Canadian Light Source have been used in conjunction with a multi coincidence time and position sensitive detection apparatus to observe the dissociative ionization of OCS. By varying the X-ray…

Kinetic energy and angular distributions of O$^-$ ions formed by dissociative electron attachment to CO molecule have been studied for 9, 9.5, 10, 10.5, 11, 11.5 eV incident electron energies around the resonance using time sliced velocity…

Atomic and Molecular Clusters · Physics 2015-02-10 Pamir Nag , Dhananjay Nandi

Photodissociation is the dominant removal process of molecules in any region exposed to intense ultraviolet (UV) radiation. This includes diffuse and translucent interstellar clouds, dense photon-dominated regions, high velocity shocks, the…

Instrumentation and Methods for Astrophysics · Physics 2015-02-10 Ewine F. van Dishoeck , Ruud Visser

A new two-dimensional axi-symmetric ultraviolet radiative transfer code is presented, which is used to calculate photodissociation and ionization rates for use in chemistry models of flaring circumstellar disks. Scattering and absorption of…

Water photodissociation in the 114 - 144 nm UV range forms excited OH which emits at mid-infrared wavelengths via highly excited rotational lines. These lines have only been detected with Spitzer in several proto-planetary disks and shocks.…

Astrophysics of Galaxies · Physics 2023-03-08 Marion Zannese , Benoît Tabone , Emilie Habart , Franck Le Petit , Ewine F. van Dishoeck , Emeric Bron
‹ Prev 1 2 3 10 Next ›