Absolute differential and integral electron excitation cross sections for atomic nitrogen. 2. The sup 4 S sup o yields 2p sup 4 sup 4 P (. lambda. 1,135 angstrom ) transition from 30 to 100 eV

Journal Article · Wed Apr 01 00:00:00 EST 1992 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JA03157· OSTI ID:5397912

Doering, J P; Goembel, L ^[1]

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1. John Hopkins Univ., Baltimore, MD (United States)

The absolute direct differential and integral electron excitation cross sections for the atomic nitrogen {sup 4}S{sub o} {yields} 2p{sup 4} {sup 4}P ({lambda}1,135 {angstrom}) transition have been measured at incident energies of 30, 50, and 100 eV. The differential cross sections measured versus scattering angle were integrated to give the integral cross section (ICS) as a function of incident energy. The ICS has a maximum value of 0.43 {times} 10{sup {minus}16} cm{sup 2} ({plus minus}30%) near 50 eV. Above 50 eV, the direct excitation cross section is within 20% of the fluorescence cross section of Stone and Zipf (1973) when the latter is adjusted downward to take account of the recent revision of the H{sub 2} dissociative excitation benchmark cross section. At 30 eV, the direct cross section is {approximately}1/10 of the fluorescence cross section. These results show that as for the {lambda}1,200-{angstrom} N I transition cross section, there is a strong cascade contribution to the fluorescence cross section from forbidden transitions to higher states excited by low-energy electron impact near threshold; but above 50 eV, unlike the {lambda}1,200-{angstrom} N I transition cross section, there is only a small cascade contribution. The optical strength of the N I({lambda}1,135 {angstrom}) multiplet obtained from the present data is 0.1{plus minus}0.005.

• OSTI ID: 5397912
• Journal Information: Journal of Geophysical Research; (United States), Vol. 97:A4; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ELECTRON-ATOM COLLISIONS
EXCITATION
NITROGEN
AURORAE
DIFFERENTIAL CROSS SECTIONS
FLUORESCENCE
INTEGRAL CROSS SECTIONS
OSCILLATOR STRENGTHS
ATOM COLLISIONS
COLLISIONS
CROSS SECTIONS
ELECTRON COLLISIONS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
LUMINESCENCE
NONMETALS
661320* - Auroral
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664300 - Atomic & Molecular Physics- Collision Phenomena- (1992-)