Accession Number : AD0487684

Title :   THE VACUUM ULTRAVIOLET ABSORPTION OF SHOCK-HEATED VIBRATIONALLY EXCITED NITROGEN.

Descriptive Note : Technical rept.,

Corporate Author : GM DEFENSE RESEARCH LABS SANTA BARBARA CA AEROSPACE OPERATIONS DEPT

Personal Author(s) : Appleton, John P. ; Steinberg, Martin

Report Date : JUL 1966

Pagination or Media Count : 27

Abstract : Absorption coefficients of shock-heated nitrogen have been measured over a temperature range from 3500 to 10,000 K at four wavelengths: 1086, 1176, 1247, and 1334 A. The experiments were performed behind the reflected shock about 1 cm from the end wall of a 3 in. -diameter shock tube; absorption of the transmitted light was measured behind the reflected shock at times after vibrational equilibration but prior to significant dissociation. The absorption coefficients thus obtained at each wavelength indicated that the absorption was due to photoexcitation of molecules from within one or two adjacent vibrational levels of the ground electronic state, and probably other states of comparable energy. Values of electronic f-numbers for transitions were deduced from the experimental data using theoretically calculated values of the absorption coefficients per unit f-number for these bands.

Descriptors :   (*NITROGEN, EXCITATION), (*SHOCK TUBES, NITROGEN), (*ABSORPTION SPECTRA, ULTRAVIOLET SPECTROSCOPY), VIBRATION, HIGH TEMPERATURE, GROUND STATE, ELECTRON TRANSITIONS, VACUUM, HYPERSONIC FLIGHT, FLUID FLOW, THEORY.

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE