New double stage pellet injector was designed for deep plasma fuelling. A distinguishing feature of the injector is a cryogenic piston inside a pump tube. Such a piston should be used as an element of the shot for maintaining propellant gas pressure behind a pellet. Large xenon piston have been formed and accelerated in the pump tube. The helium pressure in the pump tube by acting of xenon piston increased from 0.05-0.25 MPa up to 100 MPa. This approach let us avoid piston wearing in double stage pellet injectors operating in repetitive mode.

Pump tube diameter

4 mm

Pump tube length

1500 mm

Propellant gas pressure

100 bar

Piston material

Xe (solid)

Second stage gun diameter

1.5 mm

Second stage gun length

300 mm

Pellet velocity

2.5 km/s