two versions of the focused shock waves generators have been developed. In the first version
(Fig. 7a) a cylindrical pressure wave is produced by a multi-channel discharge at a cylindrical
metallic anode covered by a thin layer of porous ceramics (composite anode). In highlyconducting water a large number of short discharge channels is created and these channels are
distributed almost homogeneously on the anode surface. Each discharge channel expands and
creates a semi-spherical pressure wave, and by superposition of all the waves a cylindrical wave
propagating from the anode is formed. The cylindrical pressure wave is focused by a metallic
parabolic reflector, and near the focus this pressure wave is transformed into a strong shock wave.
Shape of the inner reflector surface is given by the equation