  A small glass RPC filled with Ar/Isob./Freon mixture has been exposed to a UV
laser light. Avalanche and streamer regimes of discharge were reached in a
fixed region of the RPC exited by the UV. A dependence of avalanche to streamer
transition process on the laser beam intensity and on the applied high voltage
was studied. Two types of the streamer signal have been observed. Using a CCD
TV camera, pictures on multi-streamer propagation over RPC were obtained.
