INFRARED FREE-ELECTRON-LASER PHOTOLYSIS OF CFCL3 AND CF2CL2

A tunable infrared free-electron laser comprised of a train of picosec ond pulses was utilized to destroy the Freons CFCl3 and CF2Cl2 by mult iple-photon dissociation. The experiments explored the effects of lase r frequency, laser fluence, spectral bandwidth, frequency chirping, re actant partial pressure, and oxygen (or air) partial pressure. We dete rmined the optimum laser frequencies for dissociation of both of the F reons and also showed that a broader spectral bandwidth laser enhances reaction. A strong reduction of dissociation fraction with increasing pressure made infrared photodissociation of Freons at near atmospheri c pressure difficult. Improvement of the high-pressure photolysis woul d require a laser macropulse much shorter than the 2 mu s used in thes e experiments.