| Spectroscopic and kinetic studies of three halogen laser systems were performed. Important energy transfer processes of the chemical oxygen iodine laser (COIL) were investigated at room temperature and at low temperatures. Rotational and vibrational energy transfer rate constants for I2(X,v=23 J=57) were measured at room temperature for collisions with He, Ar, N 2, O2, Cl2, I2, and H2O. These results together with previously recorded energy transfer data for I 2(X,v=38) provided information regarding the inelastic collision dynamics of highly excited I2(X). Vibrational relaxation of I2(X,v=23) and I2(X,v=42) induced by collisions with helium and argon at 5 K and 13 K, respectively, was examined. This investigation provided insight into the low energy collision dynamics of highly excited I2(X). Energy transfer between I(2P1/2) and O2(X) was investigated near 150 K. The rate constant for electronic energy transfer was found to be smaller than previous estimates. Laser induced fluorescence (LIF) detection of I(2P1/2) via the 5p46s( 2P3/2)-5p5(2P1/2) transition was demonstrated. The 5p5(2P 1/2) F=2 and F=3 hyperfine sublevels were resolved in the LIF spectrum, permitting observation of the kinetics associated with transfer between F=2 and 3. I(2P1/2) was generated by 498 nm photolysis of I2. The nascent population distribution of the hyperfine levels was found to be nonstatisical. Collisions with O2(X) caused F=3F=2 transfer. Hyperfine level relaxation of I(2 P1/2) by O2(X) was investigated over the temperature range 10–295 K. The hyperfine transfer rate constants were found to be insensitive to temperature over this range. Electronic energy transfer from NCl(a1Δ) to I2(X) was investigated in support of the development of the chemical azide iodine laser (CAIL). This process found to be slow. Laser excitation spectroscopy was used to investigate the Br2 D′2g(3P 2)-A′2u(3Π) transition, upon which lasing has been demonstrated. The analysis of the excitation data along with previously recorded emission data provided a comprehensive description of both states. |
