Status of the Russian pellet injector R&D program for plasma fuelling

Basic trends of research within the Russian pellet injector R&D program for 1999–2001 are discussed. The attention is focused on injectors with a screw extruder and those with a porous generator capable of injecting pellets in a repetitive continuous steady state mode. Over 12 000 deuterium pellets of 2 mm diameter were produced and accelerated to 200 m/s at a rate of 10 Hz with a reliability over 99% by a pneumatic injector equipped with a screw extruder. Over 2000 hydrogen pellets of 2.4 mm diameter and 4 mm length were accelerated to 1 km/s at a rate of 0.3–0.8 Hz by a pneumatic injector equipped with a porous generator with no moving parts. The injector designs and experimental results are presented and a concept of a new centrifuge pellet injector is discussed.