Recent Advances in DC Methods of Particle Acceleration

Four recent developments have contributed significantly to broadening the scope of dc particle-acceleration systems: 1. Tandem principle of utilizing the generated high-voltage several times; 2. Insulating-core transformer for generating high-voltage dc power; 3. Inclined-field acceleration tube that minimizes the "total voltage effect, a previous limitation of dc acceleration systems; 4. Ion-source and beam-optical designs to increase useful ion intensities and to improve efficiency of transporting accelerated dc beams. These developments are currently being incorporated, in various combinations, into several dc accelerator designs, including: a. Sub-Mev electron and positive-ion accelerators with high beam power; b. Tandem Van de Graaff accelerators with at least 10 million-volt potential; c. Powerful Tandem accelerator at moderate voltage and very high current. Typical systems arising out of these advances are described in the light of applications now being exploited in research and industry.