Crossed beam reactive scattering of oxygen atoms and surface scattering studies of gaseous condensation
A high pressure, radio frequency discharge nozzle beam source was developed for the production of very intense (greater than or equal to 10/sup 18/ atoms sr/sup -1/ sec/sup -1/) supersonic beams of oxygen atoms. This source is capable of producing seeded beams of ground state O(/sup 3/P/sub J/) atoms when dilute oxygen-argon mixtures are used, with molecular dissociation levels exceeding 80% being realized for operation at pressures up to 350 torr. When dilute oxygen-helium mixtures are employed both ground state O(/sup 3/P/sub J/) and excited state O(/sup 1/D/sub 2/) atoms are present in the terminal beam, with molecular dissociation levels typically exceeding 60% being achieved for operation at pressures up to 200 torr. Atomic oxygen mean translational energies from 0.14 to 0.50 eV were obtained using the seeded beams technique, with Mach numbers as high as 10 (FWHM ..delta.. v/v approx. = 20%) being realized. The IC1, CF/sub 3/I, C/sub 6/H/sub 6/, and C/sub 6/D/sub 6/ reactions are discussed in detail. The IC1 and CF/sub 3/I studies have enabled us to determine an improved value for the bond energy of the IO radical: D/sub o/(IO) = 55 +- 2 kcal/mole. The IO product angular and velocity distributions have been used to generate center-of-mass flux contour maps, which indicate that these two reactions proceed via relatively long-lived collision complexes whose mean lifetimes are slightly shorter than their respective rotational periods. The O(/sup 3/P/sub J/) + C/sub 6/H/sub 6/ and C/sub 6/D/sub 6/ reactions were studied in order to elucidate the reaction mechanism, and, in particular, to identify the primary reaction products produced in these reactions. Finally, a series of beam-surface scattering experiments are described which examined the internal and translational energy dependence of molecular condensation probabilities for collisions involving either CC1/sub 4/ or SF/sub 6/ and their respective condensed phases. 117 references. (JFP)
- Research Organization:
- California Univ., Berkeley (USA). Lawrence Berkeley Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5909742
- Report Number(s):
- LBL-9811
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
AROMATICS
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
ATOMIC BEAM SOURCES
BEAMS
BENZENE
CARBON TETRACHLORIDE
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
CHLORINATED ALIPHATIC HYDROCARBONS
COLLIDING BEAMS
COLLISIONS
CRYOGENIC FLUIDS
DATA
DATA FORMS
DESIGN
DEUTERIUM COMPOUNDS
DISTRIBUTION
ELEMENTS
ENERGY DEPENDENCE
ENERGY LEVELS
ENERGY RANGE
EV RANGE
EXCITED STATES
EXPERIMENTAL DATA
FLUID FLOW
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
FLUX DENSITY
GRAPHS
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
KINETICS
LIFETIME
MAPS
MILLI EV RANGE
MOLECULE COLLISIONS
NONMETALS
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN
PERFORMANCE
PROBABILITY
RADICALS
REACTION KINETICS
REFLECTION
ROTATIONAL STATES
SCATTERING
SULFUR COMPOUNDS
SULFUR FLUORIDES
SUPERSONIC FLOW
SURFACES
VELOCITY