1. AN APPARATUS FOR GENERATING HIGH-PRESSURE SHOCK WAVES WHICH COMPRISES A DRIVEN PLATE; A LAYER OF PASSIVE BUFFER MATERIAL IN CONTACT WITH A HORIZONTAL SURFACE OF SAID DRIVEN PLATE AND FORMING A SUBSTANTIALLY CONTINUOUS INTERFACE THEREWITH, THE BUFFER MATERIAL HAVING A LOWER SHOCK IMPEDANCE THAN SAID DRIVEN PLATE; A DRIVER PLATE OF HIGHER SHOCK IMPEDANCE THAN THE BUFFER MATERIAL AND GREATER THICKNESS THAN SAID DRIVEN PLATE, A HORIZONTAL SURFACE OF SAID DRIVER PLATE FACING AND BEING SPACED FROM THE FREE HORIZONTAL SURFACE OF SAID LAYER, SAID SURFACE HAVING THE SAME CONTOUR; AND MEANS FOR IMPELLING SAID DRIVER PLATE AGAINST SAID LAYER OF BUFFER MATERIAL SO THAT SAID FREE SURFACE OF SAID LAYER IS IMPACTED BY SAID HORIZONTAL SURFACE OF SAID DRIVER PLATE, SAID DRIVEN PLATE AND LAYER BEING FREELY MOVEABLE IN THE GENERAL DIRECTION FACED BY SAID DRIVEN PLATE''S FREE HORIZONTAL SURFACE.