Molecular beam measurements of inelastic cross sections for transitions between defined rotational states (j,m) of CsF in collisions with He, Ne, Ar, Kr, CH4, CF4, SF6, C2H6, N2, CO, CO2, N2O, CH3Cl, CH3Br, CF3H, and CF3Br

1979 ◽  
Vol 71 (4) ◽  
pp. 1722-1739 ◽  
Author(s):  
U. Borkenhagen ◽  
H. Malthan ◽  
J. Peter Toennies
Keyword(s):  
Cross Sections ◽  
Molecular Beam ◽  
Rotational States

Crossed-beam studies of radical reaction dynamics:

1994 ◽  
Vol 72 (3) ◽  
pp. 660-672 ◽  
Author(s):  
R. Glen Macdonald ◽  
Kopin Liu Argonne ◽  
David M. Sonnenfroh ◽  
Di-Jia Liu
Keyword(s):  
Cross Sections ◽  
Molecular Beam ◽  
Radical Reaction ◽  
Reaction Cross ◽  
Translational Energy ◽  
Vibronic State ◽  
State Distribution ◽  
Title Reaction ◽  
Vibrational Ground State ◽  
Reaction Cross Sections

The title reaction has been studied in a crossed molecular beam apparatus. Both the product state distributions and the translational energy dependence of the reaction cross sections were measured under single collision conditions. Excellent agreement was found over a wide temperature range (26–3800 K) between rate constants deduced from the translational excitation function and recent thermal kinetic data. The rotational state distribution was found to be very cold compared to the reaction exothermicity, and could be described by a Boltzmann temperature of 110 K for all K-doublet levels. The vibronic state distribution was also found to be cold, with 70% of the products formed in the vibrational ground state. By comparing the molecular beam results for vibronic state distributions with those obtained from recent bulb experiments, it was conjectured that there appears to be a strong correlation between rotation in the reactants and bending excitation in the products.

scholarly journals Dissociative Recombination of CH+ Molecular Ion Induced by Very Low Energy Electrons

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 82 ◽  
Author(s):  
Zsolt J. Mezei ◽  
Michel D. Epée Epée ◽  
Ousmanou Motapon ◽  
Ioan F. Schneider
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Incident Energy ◽  
Dissociative Recombination ◽  
Boltzmann Distribution ◽  
Rate Coefficients ◽  
Rotational States ◽  
Low Energy Electrons ◽  
Quantum Defect Theory ◽  
Π State

We used the multichannel quantum defect theory to compute cross sections and rate coefficients for the dissociative recombination of CH + initially in its lowest vibrational level v i + = 0 with electrons of incident energy below 0.2 eV. We have focused on the contribution of the 2 2 Π state which is the main dissociative recombination route at low collision energies. The final cross section is obtained by averaging the relevant initial rotational states ( N i + = 0 , ⋯ , 10 ) with a 300 K Boltzmann distribution. The Maxwell isotropic rate coefficients for dissociative recombination are also calculated for different initial rotational states and for electronic temperatures up to a few hundred Kelvins. Our results are compared to storage-ring measurements.

Helium Atom Scattering from Cyclopentane, Pyrrolidine and Tetrahydrofurane in Crossed Molecular Beams

1997 ◽  
Vol 52 (5) ◽  
pp. 425-431
Author(s):  
Christian Gebauer ◽  
Olaf Klein ◽  
Ralf Schmidt ◽  
Wolfhart Seidel
Keyword(s):  
High Resolution ◽  
Helium Atom ◽  
Cross Sections ◽  
Differential Cross ◽  
Molecular Beam ◽  
Molecular Beams ◽  
Geometric Transformation ◽  
Helium Atom Scattering ◽  
Helium Atoms ◽  
Atom Scattering

Abstract Scattering of helium atoms by cyclopentane, pyrrolidine and tetrahydrofurane molecules was ob-served in crossed molecular beam experiments. The intensity of scattered helium atoms, depending on the scattering angle, was measured with high resolution, and the damping of the diffraction oscillations of the differential cross sections was used to extract elastic anisotropic interaction potentials for these molecules. The evaluation included a geometric transformation concerning the puckered states of the envelope and the twisted conformation of the molecules. The potentials were found to be rather similar.

scholarly journals O(3P) + CO2 scattering cross-sections at superthermal collision energies for planetary aeronomy

2019 ◽  
Vol 491 (4) ◽  
pp. 5650-5659 ◽  
Author(s):  
Marko Gacesa ◽  
R J Lillis ◽  
K J Zahnle
Keyword(s):  
Cross Sections ◽  
Potential Energy Surfaces ◽  
Energy Transport ◽  
Basis Set ◽  
Planar Geometry ◽  
Rotational States ◽  
Mass Scaling ◽  
Linear Configuration ◽  
Energy Surfaces ◽  
Scattering Cross Sections

ABSTRACT We report new elastic and inelastic cross-sections for O(3P) + CO2 scattering at collision energies from 0.03 to 5 eV, of major importance to O escape from Mars, Venus, and CO2-rich atmospheres. The cross-sections were calculated from first principles using three newly constructed ab initio potential energy surfaces correlating to the lowest energy asymptote of the complex. The surfaces were restricted to a planar geometry with the CO2 molecule assumed to be in linear configuration fixed at equilibrium. Quantum-mechanical coupled-channel formalism with a large basis set was used to compute state-to-state integral and differential cross-sections for elastic and inelastic O(3P) + CO2 scattering between all pairs of rotational states of CO2 molecule. The elastic cross-sections are 35 per cent lower at 0.5 eV and more than 50 per cent lower at 4 + eV than values commonly used in studies of processes in upper and middle planetary atmospheres of Mars, Earth, Venus, and CO2-rich planets. Momentum transfer cross-sections, of interest for energy transport, were found to be proportionally lower than predicted by mass scaling.

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