Vibrational energy transfer in gas phase water and ammonia
The V ..-->.. T, R relaxation rate for NH/sub 3/ (..nu../sub 2/) was studied from 198/sup 0/K to 398/sup 0/K by the method of laser-excited vibrational fluorescence. The self-deactivation rate constant decreases from 2.4 ..mu..sec torr/sup -1/ at 198/sup 0/K to 0.65 ..mu..sec/sup -1/ torr/sup -1/ at 398/sup 0/K. The rate constants for deactivation by He, Ar, N/sub 2/, and O/sub 2/ are much smaller and show a weak temperature dependence in the opposite direction. The vibrational relaxation rates of the coupled ..nu../sub 1/, ..nu../sub 3/ stretching level manifold and of the 2..nu../sub 2/ bending level in H/sub 2//sup 18/O was studied from 250/sup 0/K to 400/sup 0/K using th same method as for NH/sub 3/. The ..nu../sub 1/, ..nu../sub 3/ self-deactivation rate goes from 1.4 ..mu..sec/sup -1/ torr/sup -1/ at 250/sup 0/K to 0.48 ..mu..sec-/sup 1/ torr-/sup 1/ at 400/sup 0/K. For 2..nu../sub 2/ it goes from 4.5 ..mu..sec-/sup 1/ torr to 1.9 ..mu..sec/sup -1/ torr/sup -1/. The temperature dependence of the deactivation of both levels by He and Ar is much weaker and the rates are several hundred times slower. Deactivation of ..nu../sub 1/, ..nu../sub 3/ by N/sub 2/, O/sub 2/, and CO/sub 2/ is measured only at 293/sup 0/K. N/sub 2/ and O/sub 2/ deactivate ..nu../sub 1/, ..nu../sub 3/ about 5 and CO/sub 2/ about 50 times faster than He or Ar.
- Research Organization:
- California Univ., Berkeley (USA). Lawrence Berkeley Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5865475
- Report Number(s):
- LBL-9955
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
AMMONIA
ARGON
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
COLLISIONS
CRYOGENIC FLUIDS
DATA
DATA FORMS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EXCITED STATES
EXPERIMENTAL DATA
FLUIDS
FLUORESCENCE
GASES
GRAPHS
HELIUM
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
ISOLATED VALUES
ISOTOPES
LASER RADIATION
LIGHT NUCLEI
LUMINESCENCE
MOLECULE COLLISIONS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
NUCLEI
NUMERICAL DATA
OXYGEN
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
RADIATIONS
RARE GASES
RELAXATION
ROTATIONAL STATES
STABLE ISOTOPES
TIME DEPENDENCE
VIBRATIONAL STATES
WATER