Accession Number : AD0914490

Title :   Vacuum Ultraviolet Spectral Studies.

Descriptive Note : Final rept. May 72-Jul 73,

Corporate Author : TRW SYSTEMS GROUP REDONDO BEACH CA

Personal Author(s) : Shackleford, William L.

Report Date : 25 OCT 1973

Pagination or Media Count : 60

Abstract : The significance of this research to the Air Force is that it contributes to the understanding of the mechanism of vacuum ultraviolet (VUV) emission from flames and rocket exhausts. Quantitative data is presented on the rates of specific chemiluminescence reactions involving C2O and CH2 radicals. The measurements were carried out in fast flow systems in which photolysis of C3O2 or ketene provided controllable concentrations of C2O or CH2 radicals, respectively, in the presence of measured concentrations of O, O2 and He molecules. A mass spectrometer was employed in order to measure the amount of photodissociation of C3O2, which was shown to be approximately equal to the number of C3O2 molecules absorbing UV photons. An important result of these experiments was the observation that the intensity of chemiluminescence from photolyzed C3O2/O mixtures increases significantly with the concentration of diluent He atoms. It was also found that the intensity of chemiluminescence is insensitive to the wavelength at which C3O2 photolysis occurs in the 2300 < wavelength < 3000A interval. These results indicate that singlet C2O (1) molecules were probably participating in the chemiluminescence. Absolute measurements of the CO fourth positive emission intensity were obtained, and the data indicate that the rate constant for population of highly excited CO* levels could be 10 to the-12th power cc/molecule/sec or more at 300K.

Descriptors :   *EMISSIVITY), *ULTRAVIOLET RADIATION), (*EXHAUST GASES, (*EXHAUST FLAMES, (*CARBON COMPOUNDS, OXIDES), (*CHEMILUMINESCENCE, EXHAUST GASES), FREE RADICALS, HYDROCARBONS, OXIDATION, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA, PHOTOLYSIS, REACTION KINETICS, HELIUM, OXYGEN, ROCKET ENGINES, DISSOCIATION, MOLECULAR ENERGY LEVELS, FLAMES.

Subject Categories : Ultraviolet Detection and Detectors
      Atomic and Molecular Physics and Spectroscopy
      Optics
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE