Electron impact study of the 100 eV emission cross section and lifetime of the Lyman‐Birge‐Hopfield band system of N 2 : Direct excitation and cascade

2017 ◽  
Vol 122 (6) ◽  
pp. 6776-6790 ◽  
Author(s):  
J. M. Ajello ◽  
C. P. Malone ◽  
G. M. Holsclaw ◽  
A. C. Hoskins ◽  
R. W. Eastes ◽  
...  
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Band System ◽  
Emission Cross Section ◽  
Impact Study ◽  
Direct Excitation

Absolute cross sections for D2 Lyman and Werner band excitation by controlled electron impact

1984 ◽  
Vol 62 (1) ◽  
pp. 1-9 ◽  
Author(s):  
K. Becker ◽  
J. W. McConkey
Keyword(s):  
Energy Range ◽  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Impact Energy ◽  
Emission Cross Section ◽  
Direct Excitation ◽  
The Cross ◽  
Impact Energies

We have studied the Lyman [Formula: see text] and Werner [Formula: see text] band emissions produced by 20–500-eV electrons incident on molecular deuterium, D2. Emission cross sections of (3.7 ± 0.9) × 10−17 cm2 for the B → X and (3.54 ± 0.74) × 10−17 cm2 for the C → X system have been determined at 100-eV impact energy. Cascading did not play an important role in the [Formula: see text] emission, but it was shown to affect the [Formula: see text] emission seriously, particularly for impact energies below 50 eV. We estimate the cross section for direct excitation of the [Formula: see text] state and the cascade cross section to be 2.95 × 10−17 and 0.75 × 10−17 cm2, at 100 eV respectively. The cascade cross section is 20 ± 10% of the total B → X emission cross section, and is essentially constant in the energy range 300–50 eV, but increases significantly for lower impact energies, e.g., to 40 ± 15% at 27.5 eV. The cross section for the atomic 2p → 1s Lyman α emission from D2 has also been measured and the value of 1.00 × 10−17 cm2 at 100 eV is 20% smaller than the cross section for Lyman α emission from H2.

Absolute emission cross section for electron-impact excitation ofLi+to the (2P3) level

1978 ◽  
Vol 18 (4) ◽  
pp. 1353-1362 ◽  
Author(s):  
Wade T. Rogers ◽  
J. Østgaard Olsen ◽  
Gordon H. Dunn
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Emission Cross Section ◽  
Impact Excitation ◽  
Electron Impact Excitation

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.

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