scholarly journals Theoretical resonant electron-impact vibrational excitation, dissociative recombination and dissociative excitation cross sections of ro-vibrationally excited BeH+ ion

2017 ◽  
Vol 59 (4) ◽  
pp. 045008 ◽  
Author(s):  
V Laporta ◽  
K Chakrabarti ◽  
R Celiberto ◽  
R K Janev ◽  
J Zs Mezei ◽  
...  
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Vibrational Excitation ◽  
Dissociative Recombination ◽  
Dissociative Excitation ◽  
Vibrationally Excited ◽  
Excitation Cross Sections ◽  
Resonant Electron

Measurement of absolute electron-impact excitation cross sections in Ar and N2 using H and H2 emissions as secondary standards

1988 ◽  
Vol 66 (4) ◽  
pp. 349-357 ◽  
Author(s):  
J. L. Forand ◽  
S. Wang ◽  
J. M. Woolsey ◽  
J. W. McConkey
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Emission Cross Section ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Dissociative Excitation ◽  
Excitation Cross Sections ◽  
Line Following ◽  
Good Agreement

A detailed description is given of a technique in which emissions from H and H2 are used to calibrate an apparatus used for electron-impact emission cross-section measurements in the wavelength range 90–130 nm. Absolute emission cross sections have been measured at 200 eV electron-impact energy for the 120 nm N I line following dissociative excitation of N2 and for the Ar and Ar+ lines at 104.8, 106.7, 92.0, and 93.8 nm respectively. Good agreement with earlier works is obtained in the case of the N I line when earlier data are renormalized to take into account the recent revision of the cross section for production of Lyman α from H2. Measurements of the 104.8 and 106.7 nm lines suggest a 40% cascade component for the latter line at energies of 200 eV and above.

scholarly journals Rotational and Vibrational Excitation of Nitrogen by Electron Impact

1997 ◽  
Vol 50 (3) ◽  
pp. 441 ◽  
Author(s):  
A. G. Robertson ◽  
M. T. Elford ◽  
R. W. Crompton ◽  
Michael A. Morrison ◽  
Weiguo Sun ◽  
...  
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Unsolved Problem ◽  
Vibrational Excitation ◽  
Rotational Excitation ◽  
Early Analysis ◽  
Excitation Cross Sections ◽  
Low Energy Electron ◽  
Experimental Values ◽  
Best Fit

Rotational excitation of nitrogen by low-energy electron impact has posed an unsolved problem for more than three decades. Early analysis of the results of swarm experiments in nitrogen found that the data could be matched remarkably well by assuming that the energy dependences of the Δj = 2 cross sections from threshold to a few tenths of an eV are given by a simple formula based on the Born approximation. Moreover, the quadrupole moment (the only adjustable parameter in the formula) which gave the best fit to the data was commensurate with existing experimental values. This finding posed an enigma, since the quadrupole Born expression is known to incorrectly represent the interaction potential for scattering except within a few meV of threshold. We have analysed new swarm data, taken in a dilute mixure of nitrogen in neon, using theoretical rotational and momentum transfer cross sections based on a solution of the Schrödinger equation using static, exchange, and polarisation potentials. This work explains the long-standing enigma and provides the basis for a subsequent analysis in which theoretical vibrational excitation cross sections are also investigated using the new swarm data for the mixture.

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