Formation cross sections, emission cross sections and Fano plots of translational-energy-separated excited hydrogen atoms (n = 3,4) produced in e-H2O collisions

1992 ◽  
Vol 168 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Teiichiro Ogawa ◽  
Satoru Ihara ◽  
Nobuaki Yonekura ◽  
To-oru Yasuda ◽  
Keiji Nakashima
Keyword(s):  
Cross Sections ◽  
Translational Energy ◽  
Hydrogen Atoms

Photoinduzierte Stoßprozesse metastabiler Wasserstoffatome mit H2 im Energiebereich von 0,05 — 0,47 eV

1969 ◽  
Vol 24 (4) ◽  
pp. 587-596 ◽  
Author(s):  
F. J. Comes ◽  
U. Wenning
Keyword(s):  
Electric Fields ◽  
Cross Sections ◽  
Collision Cross Section ◽  
Translational Energy ◽  
Selective Absorption ◽  
Hydrogen Atoms ◽  
Excited Atoms ◽  
Hydrogen Molecules ◽  
Vibrational Levels ◽  
The Difference

Abstract Molecular hydrogen was excited by selective absorption of ultraviolet radiation of appropriate wavelength into the vibrational levels ν′ 3, 4, and 5 of the electronic D (1IIu)-state. For the radiation bandwidth chosen the molecule was only formed in the rotational levels J = 1 and 2 of the R-branch. The excited molecules decay by predissociation into two hydrogen atoms of translational energy which is equal to one half of the difference between the excitation and dissociation energies. One of the atoms is formed in its first excited state. The formation of the excited species can be proven by its fluorescence (Lymanα-radiation). As a result the measurements show, that the excited atoms are all in the metastable 2S-state and not in the short-lived 2P -state. Without electric fields these metastable atom s loose their excitation energy in collisions with the surrounding hydrogen molecules. One part (a) follows an induced transition to the electronic ground state by the emission of Lyα-radiation (1216 Å), the other part (b) is transformed to products or undergoes an energy transfer process without emitting Lyα-radiation. If a quenching field is applied spontaneous emission will compete with collisional deactivation, which allows the deactivation cross sections to be calculated. These cross sections are between 50 and 100 Å2 (a) and about 50 Å2 in case (b). In case (a) the collision cross section increases with the velocity of the particles whereas in case (b) a constant value was found.

Translational-Energy-Dependent Emission Cross Sections of Excited Hydrogen Atoms Produced in Electron-Methane, Ethane, Ethylene and Acetylene Collisions

1993 ◽  
Vol 32 (Part 1, No. 7) ◽  
pp. 3296-3299 ◽  
Author(s):  
Nobuaki Yonekura ◽  
Toshiyuki Tsuboi ◽  
Hideaki Tomura ◽  
Keiji Nakashima ◽  
Junichi Kurawaki ◽  
...  
Keyword(s):  
Cross Sections ◽  
Translational Energy ◽  
Hydrogen Atoms ◽  
Energy Dependent

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.

Spin-change cross sections between hydrogen atoms

1964 ◽  
Vol 83 (1) ◽  
pp. 157-158 ◽  
Author(s):  
A Dalgarno ◽  
R J W Henry
Keyword(s):  
Cross Sections ◽  
Hydrogen Atoms
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