抄録
Investigation on ozone effective lifetimes in ozone-oxygen gas mixtures contained in a cylindrical cell as a function of pressure and temperature is carried out. Effective lifetimes are determined by tracking the time decay of the ozone density in the cell which is measured by the HgI photo-absorption method. The decay curves were measured over long periods of time reaching 105s, while the ozone densities varied in the range 1016-1014cm-3. Variation of the decay rate with time and ozone density along single decay curves as well as gradual change of the effective lifetimes of ozone in successively repeated measurements was observed, likely due to variations of the wall surface properties. The loss rate of ozone was attributed to two processes: sticking and decomposition of ozone molecules at the cell wall surface and decomposition in reactions with oxygen in the gas phase. In this work, we obtained results on the temperature dependence of ozone loss rate in the range of 293-353K. From the measured data, the reaction rate coefficient of ozone molecules with oxygen in the gas phase is determined as kp = 2.33×10-23 exp (-1700/T) cm3/s.
