A pneumatic injector of deuterium pellets for fusion devices

A new deuterium pellet injector intended for maintaining a steady-state fusion reaction in a plasma is described. A technique for producing pellets by continuous solid deuterium extrusion was developed. A 2-mm-diameter cylindrical rod made from transparent solid deuterium was continuously pushed out of a screw extruder for 3000 s at a speed of 10–40 mm/s. Over 16000 deuterium pellets 2 mm in size were produced in the injector in the steady-state mode. They were continuously injected into the diagnostic chamber for 2000 s at a rate of 1–12 Hz and speed of 200–600 m/s. More than 12500 pellets were injected at a rate of 10 Hz in the steady-state mode, and 99% of them were intact.