A multi-barrel pellet injector system has been developed for plasma fueling of the tokamak fusion test reactor (TFTR). This paper describes the different arrangement of barrels along with design of sleeve for holding the barrels, for production and acceleration of pellets of different sizes. The in situ pipe gun concept with the use of compact cryo-coolers enables stable operation as a fundamental facility in plasma experiments. Pellets are accelerated in long gun barrels with compressed gas (at high pressures) to velocities in the range 1.0–4.0 km/s. The pellets are transported to the plasma in an injection line that incorporates two stages of guide tubes with intermediate vacuum pumping stations. A remote, stand-alone control and data-acquisition system is used for injector and vacuum system operation. The design features of the pellet injector system are described.Keywords: Cryo-cooler, pellet, sleeve, barrel arrangement, injector system
