Rotational Energy Distributions of Benzene Liberated from Aqueous Liquid Microjets: A Comparison between Evaporation and Infrared Desorption

2006 ◽  
Vol 59 (2) ◽  
pp. 104 ◽  
Author(s):  
Olivia J. Maselli ◽  
Jason R. Gascooke ◽  
Sarah L. Kobelt ◽  
Gregory F. Metha ◽  
Mark A. Buntine
Keyword(s):  
Laser Pulse ◽  
Rotational Temperature ◽  
Rotational Energy ◽  
Vibronic Band ◽  
Energy Distributions ◽  
Rotational States ◽  
Ir Laser ◽  
Equilibrium Evaporation ◽  
Spectral Profiles ◽  
Liquid Microjets

We have measured the rotational energy distribution of benzene molecules both evaporated and desorbed by an IR laser from a liquid microjet. Analysis of the 601 vibronic band of benzene has shown that the benzene molecules evaporating from the liquid microjet surface have a rotational temperature of 157 ± 7 K. In contrast, the rotational temperature of benzene molecules desorbed from the liquid microjet by a 1.9 μm laser pulse is 82 ± 5 K. However, in both cases careful inspection of the spectral profiles shows that the experimental rotational distributions are non-Boltzmann, displaying an underpopulation of high rotational states and a relative overpopulation of the low rotational states. The non-equilibrium evaporation and desorption spectral profiles are consistent with a model that involves transfer of internal energy into translation upon liberation from the condensed phase.

ABOVE THRESHOLD IONIZATION OF POLAR NaK MOLECULES DRIVEN BY FEW-CYCLE LASER PULSE

2010 ◽  
Vol 09 (04) ◽  
pp. 785-795 ◽  
Author(s):  
JIE YU ◽  
CHUAN-CUN SHU ◽  
WEN-HUI HU ◽  
SHU-LIN CONG
Keyword(s):  
Laser Pulse ◽  
Degrees Of Freedom ◽  
Rotational Temperature ◽  
Threshold Ionization ◽  
Rotational States ◽  
Above Threshold Ionization ◽  
Rotational Degrees Of Freedom ◽  
Left And Right ◽  
The Right ◽  
Continuum Wave

We investigate theoretically the above-threshold ionization (ATI) of the polar NaK molecule exposed in few-cycle laser field by numerically solving the time-dependent Schrödinger equation including the vibrational and rotational degrees of freedom. The left and right ATI spectra are calculated by integrating the ionization continuum wave function over the left and the right half spheres along the laser polarization. We find that the left and right ATI spectra are asymmetric, and this asymmetry depends strongly on the molecular orientation and the carrier-envelope phase (CEP) of the laser pulse. Moreover, we also perform the calculation for different initially rotational states to study the effect of rotational temperature on the ATI dynamics.

Statistical physics of two-temperature rotational energy distributions in stationary plasmas

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Marco Antonio Ridenti ◽  
Jayr de Amorim ◽  
Carlos Alberto Bomfim Silva ◽  
Jan Voráč ◽  
Carlos Eduardo Fellows ◽  
...  
Keyword(s):  
Statistical Physics ◽  
Rotational Energy ◽  
Energy Distributions ◽  
Two Temperature

scholarly journals Dirty H2 Molecular Clusters as the DIB Sources: Spectroscopic and Physical Properties

2013 ◽  
Vol 9 (S297) ◽  
pp. 378-380
Author(s):  
L. S. Bernstein ◽  
F. O. Clark ◽  
D. K. Lynch
Keyword(s):  
Single Molecule ◽  
Molecular Clouds ◽  
Rotational Temperature ◽  
Single Layer ◽  
Molecular Clusters ◽  
Microwave Emission ◽  
Giant Molecular Clouds ◽  
Induced Dipole ◽  
Spectral Profiles ◽  
Uv Photons

AbstractWe propose that the diffuse interstellar bands (DIBs) arise from absorption lines of electronic transitions in molecular clusters primarily composed of a single molecule, atom, or ion (“seed”), embedded in a single-layer shell of H2 molecules (Bernstein et al. 2013). Less abundant variants of the cluster, including two seed molecules and/or a two-layer shell of H2 molecules may also occur. The lines are broadened, blended, and wavelength-shifted by interactions between the seed and surrounding H2 shell. We refer to these clusters as CHCs (Contaminated H2 Clusters). CHC spectroscopy matches the diversity of observed DIB spectral profiles, and provides good fits to several DIB profiles based on a rotational temperature of 10 K. CHCs arise from ~cm-sized, dirty H2 ice balls, called CHIMPs (Contaminated H2 Ice Macro-Particles), formed in cold, dense, Giant Molecular Clouds (GMCs), and later released into the interstellar medium (ISM) upon GMC disruption. Attractive interactions, arising from Van der Waals and ion-induced dipole potentials, between the seeds and H2 molecules enable CHIMPs to attain cm-sized dimensions. When an ultraviolet (UV) photon is absorbed in the outer layer of a CHIMP, it heats the icy matrix and expels CHCs into the ISM. While CHCs are quickly destroyed by absorbing UV photons, they are replenished by the slowly eroding CHIMPs. Since CHCs require UV photons for their release, they are most abundant at, but not limited to, the edges of UV-opaque molecular clouds, consistent with the observed, preferred location of DIBs. An inherent property of CHCs, which can be characterized as nanometer size, spinning, dipolar dust grains, is that they emit in the radio-frequency region. Thus, CHCs offer a natural explanation to the anomalous microwave emission (AME) feature in the ~10-100 GHz spectral region.

Initial vibrational and rotational energy distributions of hydrogen fluoride produced in reactions F + H · R, where R = H, CH3, C2H5and CHO

1978 ◽  
Vol 74 (0) ◽  
pp. 2158-2169 ◽  
Author(s):  
Peter Beadle ◽  
Michael R. Dunn ◽  
Neville B. H. Jonathan ◽  
John P. Liddy ◽  
John C. Naylor ◽  
...  
Keyword(s):  
Hydrogen Fluoride ◽  
Rotational Energy ◽  
Energy Distributions
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