A screw extruder for the centrifugal injector of hydrogen and deuterium pellets for the JT-60U tokamak

A compact extruder producing 150–200 mm³/s of transparent solid hydrogen or deuterium ice in a continuous steady-state mode at temperatures of 11–12 and 13–15 K, respectively, has been developed. A system for measuring the extrusion speed at an error of 1% is described. Solid hydrogen or deuterium has been continuously extruded for 600–1000 s at velocities of movement of a solid rod at the extruder outlet of 39 ± 3 and 38 ± 2 mm/s, respectively.