Shock wave focusing by curved walls and staging of beam induced thermonuclear microexplosions

Because of the technical difficulties associated with the production of ultrashort beam pulses, the efforts to release energy from thermonuclear microexplosions are mainly directed at present towards confinement in a high-Z material solid wall, as in the original proposal by the author for relativistic electron beam induced fusion. The most common approach today is by the implosion of a solid high-Z material shell, for example, with an intense relativistic electron beam. We will show that better utilization of the beam energy may be possible with beam bombardment of a curved concave wall, setting off a shock wave which can be focused precisely onto the thermonuclear target. In addition, by a proper variation of the atomic weight and density in the layer of the wall material to be ablated by the energy deposition of the beam, the pulse length of the shock wave can be made substantially shorter than the pulse length of the beam.