Improved two-stage gun for pellet injection

The injection of high speed (over 2000 m/s) hydrogen pellets in plasma machines is a difficult task, especially due to the poor mechanical strength of solid hydrogen, which imposes limits on the acceleration of the pellets. In this work a method for shaping the acceleration law using a two-piston pneumatic injector is described. Numerical and experimental runs with plastic pellets have been performed. Also, some preliminary experimental results with deuterium pellets are presented.