Intensity ratios within the Balmer linesH ? andH ? with respect to angular momentum after dissociative excitation ofH 2 by electron impact

1983 ◽  
Vol 312 (4) ◽  
pp. 361-364
Author(s):  
J. Neumann ◽  
G. Hermann ◽  
A. Scharmann ◽  
A. Schmillen
Keyword(s):  
Angular Momentum ◽  
Electron Impact ◽  
Dissociative Excitation ◽  
Intensity Ratios

Population of 3s, 3p, and 3d Sublevels of Atomic Hydrogen after Dissociative Excitation of some Alkanes by Electron Impact

1977 ◽  
Vol 32 (7) ◽  
pp. 720-723 ◽  
Author(s):  
H. J. Hartfuß ◽  
H. Röll
Keyword(s):  
Electron Impact ◽  
Atomic Hydrogen ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Dissociative Excitation ◽  
Balmer Line ◽  
Time Resolved ◽  
Target Molecule ◽  
Intensity Ratios

AbstractThe intensity ratios within the Balmer-line Hα have been determined after pulsed electron impact excitation and dissociation of the alkanes CH4, C5H12, C6H14, C7H16, C8H18 and C9H20 . A time resolved technique has been used to separate the line-components by their different life­ times. No contribution of the 3p-level to the intensity of Hα could be detected, as was found earlier in the case of some other hydrogen containing molecules 2, 3. The ratio of the intensity contribution originating in 3s population to the total Ha intensity was found to be between 0.57 and 0.66 de­pending on the target molecule.

Intensity Ratios within the Balmer Lines Hα and Hβ After Dissociative Excitation of C6H6 and H2

1976 ◽  
Vol 31 (11) ◽  
pp. 1292-1297 ◽  
Author(s):  
H. J. Hartfuß ◽  
J. Neumann ◽  
H. D. Schneider
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Principal Quantum Number ◽  
Dissociative Excitation ◽  
Total Emission ◽  
Excitation Cross Sections ◽  
Balmer Lines ◽  
State Production ◽  
Intensity Ratios ◽  
Dissocia Tion

Abstract The decay-curves of the Balmer-lines Hα and Hβ have been measured after dissociative excitation of C6H6 and H2 by electron-impact in the 100 eV range. The analysis of the decay-curves shows, in agreement with other authors, that only the 3s-and 3d-states in the case of Hα and the 4s-and 4d-states in the case of Hβ contribute significantly to the total intensity of Hα and Hβ, respectively, but not the p-states 3p and 4p. The intensity-ratios J(3s)/J(Ha) and J(4s)/J(Hβ) have been investigated. Comparison with the total emission cross-sections of the states n=3 and n=4 allows to determine the excitation cross-sections of the sublevels 3s and 4s. It is found that s-state production is favoured in the dissocia-tion process. This seems to be independent on the principal quantum number.

Dissociative excitation of molecules electron impact

1980 ◽  
Vol 77 ◽  
pp. 773-777 ◽  
Author(s):  
F.J. de Heer ◽  
H.A. Van Sprang ◽  
G.R. Mohlmann
Keyword(s):  
Electron Impact ◽  
Dissociative Excitation

scholarly journals A physico-chemical model to study the ion density distribution in the inner coma of comet C/2016 R2 (Pan-STARRS)

2020 ◽  
Author(s):  
Susarla Raghuram ◽  
Anil Bhardwaj ◽  
Damien Hutsemékers ◽  
Cyrielle Opitom ◽  
Jean Manfroid ◽  
...  
Keyword(s):  
Density Distribution ◽  
Electron Impact ◽  
Emission Intensity ◽  
Impact Ionization ◽  
Excitation Source ◽  
Resonance Fluorescence ◽  
Ion Density ◽  
Physico Chemical ◽  
Intensity Ratios ◽  
Ion Emission

Abstract The recent observations show that comet C/2016 R2 (Pan-Starrs) has a unique and peculiar composition when compared with several other comets observed at 2.8 au heliocentric distance. Assuming solar resonance fluorescence is the only excitation source, the observed ionic emission intensity ratios are used to constrain the corresponding neutral abundances in this comet. We developed a physico-chemical model to study the ion density distribution in the inner coma of this comet by accounting for photon and electron impact ionization of neutrals, charge exchange and proton transfer reactions between ions and neutrals, and electron-ion thermal recombination reactions. Our calculations show that CO$_2^+$ and CO+ are the major ions in the inner coma, and close to the surface of nucleus CH3OH+, CH3OH$_2^+$ and O$_2^+$ are also important ions. By considering various excitation sources, we also studied the emission mechanisms of different excited states of CO+, CO$_2^+$, N$_2^+$, and H2O+. We found that the photon and electron impact ionization and excitation of corresponding neutrals significantly contribute to the observed ionic emissions for radial distances smaller than 300 km and at larger distances, solar resonance fluorescence is the major excitation source. Our modelled ion emission intensity ratios are consistent with the ground-based observations. Based on the modelled emission processes, we suggest that the observed ion emission intensity ratios can be used to derive the neutral composition in the cometary coma only when the ion densities are significantly controlled by photon and photoelectron impact ionization of neutrals rather than by the ion-neutral chemistry.

Dissociative excitation of CH4 by electron impact: Emission cross sections for the fragment species

1996 ◽  
Vol 213 (1-3) ◽  
pp. 369-384 ◽  
Author(s):  
K. Motohashi ◽  
H. Soshi ◽  
M. Ukai ◽  
S. Tsurubuchi
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Dissociative Excitation

Dissociative excitation of NO2by electron impact

2009 ◽  
Vol 42 (18) ◽  
pp. 185201 ◽  
Author(s):  
J A Young ◽  
C P Malone ◽  
P V Johnson ◽  
X Liu ◽  
J M Ajello ◽  
...  
Keyword(s):  
Electron Impact ◽  
Dissociative Excitation
Sign in / Sign up

Export Citation Format

Share Document