Intermolecular energy exchange by infrared radiometry. Final report, 1 June-31 December 1979
Excitation by translational energy of the asymmetric stretch vibrational mode of ground state carbon dioxide molecules in collision with nitrogen, oxygen and argon molecules has been studied, by intersecting two slightly collimated molecular beams in the field of view of an InSb photovoltaic detector which monitored resulting radiation in the 4.3 micrometer band. The excitation cross sections for all three combinations of partners were of similar magnitude and showed a strong dependence upon collision velocity. For nitrogen the measured cross sections ranged from about 0.0008 square Angstroms at 2 km/s to about 0.5 square Angstroms at 5 km/s. A similar but separate experiment determined an upper limit of 0.1 square Angstroms for the collisional excitation of hydrogen fluoride by krypton at energies up to 1.7 times the threshold requirement. Bulk relaxation rates for molecules in free jet expansion were also investigated. Results obtained from experimental data with the frequently used Sudden Freeze Model have been compared with those obtained by Numerical Integration. Success has been achieved in obtaining Method-of-Characteristics solutions for the free jet expansion with a varying specific heat ratio. This development provides the best description yet of relaxation in free jet expansion for any internal mode which can be characterized by a Boltzmann distribution of energy.
- Research Organization:
- Yale Univ., New Haven, CT (USA). Dept. of Engineering and Applied Science
- OSTI ID:
- 7063546
- Report Number(s):
- AD-A-082540
- Country of Publication:
- United States
- Language:
- English
Similar Records
Energy redistribution in low energy collisions between I/sub 2/* and He
Collisional energy exchange in polyatomic molecules. Final technical report, 1 January 1980-31 December 1982
Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
BEAMS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
COLLIDING BEAMS
COLLISIONS
CROSS SECTIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FLUIDS
GASES
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INFRARED RADIATION
INORGANIC ACIDS
KRYPTON
MEASURING INSTRUMENTS
MOLECULAR BEAMS
MOLECULE COLLISIONS
MOLECULE-MOLECULE COLLISIONS
NITROGEN
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
RADIATION DETECTORS
RADIATIONS
RADIOMETERS
RARE GASES
VIBRATIONAL STATES