Experimental determination of absolute differential and integral cross sections for electron-impact excitation of the allowed transitions of atomic oxygen

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6273829

Vaughan, S O

Absolute differential and integral cross sections for the ten most intense allowed transitions in atomic oxygen were measured at incident energies between 16.5 and 200 eV. The characterized transitions are the (/sup 3/P ..-->.. /sup 3/S/sup 0/) transition at 1304 A, the (/sup 3/P ..-->.. /sup 3/D/sup 0/) transition at 989 A, the three autoionizing transitions (/sup 3/P ..-->.. /sup 3/P/sup 0/) at 878, 792, and 770 A, and the Rydberg series of transitions (/sup 3/P ..-->.. /sup 3/D/sup 0/) beginning at 1027 A. A variable-angle and incident-energy electron spectrometer coupled to a microwave-discharge free-supersonic jet expansion source was used for the experiments. The differential cross sections for the (/sup 3/P ..-->.. /sup 3/S/sup 0/) transition were determined by comparison to well-characterized transitions in reference atoms such as helium, argon, and atomic hydrogen. All differential cross sections vary smoothly with the incident energy and are flatter with scattering angle at the lower incident energies as expected. The absolute integral cross sections are smooth and well defined by the data and match the shape expected for the Bethe region (incident energy > 100 eV).

• Research Organization: Johns Hopkins Univ., Baltimore, MD (USA)
• OSTI ID: 6273829
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
COLLISIONS
COMPARATIVE EVALUATIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
ELECTRON COLLISIONS
ELEMENTS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EV RANGE 10-100
EV RANGE 100-1000
EXCITATION
INTEGRAL CROSS SECTIONS
NONMETALS
OXYGEN