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The decomposition of ozone has been studied following a short duration u.v. light pulse. From an analysis of the O3 decomposition curves for O3:N2, O3:N2:O2 and O3:O2 mixtures the relative rate constant for O(singlet D) deactivation by N2 and O2 is given. It is also shown that O2(singlet Sigma(sub g)(+)) is formed in at least 75% of the collisions in which O(singlet D) is deactivated by O2. The rate constants of the reactions O2(singlet Sigma(sub g)(+)) + O3 to 2O2 + O and O + O2 + O2 to O3 + O2 are found. (Modified author abstract)

High-resolution spectra of the NO2 continuum emission produced from the reaction NO + O3 to NO2 + O2 have been investigated to detect any possible emission from O2 singlet Delta at 1270 nm or at 762 nm. The photolysis of O3/O2 mixtures at 253.7 nm, which produces both states of O2 with known quantum efficiency, has been used as an internal standard. From the results it is concluded that less than 1/300 and 1/200 of the NO + O3 reactive collisions result in production of O2 singlet Delta or Sigma states, respectively, at room temperature. (Modified author abstract)

An HF chemical laser with a 10-cm-long active volume has been constructed for operation at high pulse repetition rates using TE excitation. Up to 7.2 W of quasi-CW power were produced at 1100 Hz. Powers as high as 160 mW were obtained on a single transition when the cavity was line tuned. The effect of sequential or cascade lasing was observed. (Author)

The efficiency of formation of O2(singlet Sigma(g)(+)) by energy transfer between O(singlet D) and O2 has been measured relative to the efficiency of O2(singlet Delta (g)) formation by photolysis of zones at 2537 A. The two singlet states of molecular oxygen were formed in a flow system and their relative concentrations determined with a calibrated detection system by measuring their emission at 7620 A and 1.27 microns. The results show that if the efficiency of O2(singlet Delta (g)) formation by O3 photolysis is unity then the singlet Sigma(g)(+) state of O2 is produced in more than (85 plus or minus 15) % of the collisions deactivating O(singlet D). This determination is compared with previous results. (Author), Prepared in cooperation with Centre de Recherches sur les Atomes et les Molecules, Courcelette (Quebec).

A rate constant for the reaction O2 singlet Delta(g) + O3 to 2O2 + O over the temperature range 283-321K has been obtained. The rate of the reverse reaction was also calculated.

Photolysis of ozone oxygen mixtures at 2537A has been found to produce O2(singlet Sigma(g)(+)) and O2(singlet Delta(g)). The O2(singlet Sigma(g)) was produced by energy transfer from O(singlet D) and the O2(singlet Delta(g)) by the primary photolysis step. (Author)

Gas phase deactivation of O2 (singlet Delta(g)) has been investigated and rate constants for benzene and oxygen have been measured. Deactivation by nitrogen is much slower. (Author)