Abstract
An eight-shot pneumatic pellet injection system has been developed for plasma fueling of the tokamak fusion test reactor (TFTR). The active cryogenic mechanisms consist of a solid hydrogen extruder and a rotating pellet wheel that are cooled by flowing liquid-helium refrigerant. The extruder provides solid hydrogen for stepwise loading of eight holes located circumferentially around the pellet wheel. This design allows for three different pellet diameters: 3.0 mm (three pellets), 3.5 mm (three pellets), and 4.0 mm (two pellets) in the present configuration. Each of the eight pellets can be shot independently. Deuterium pellets are accelerated in 1.0-m-long gun barrels with compressed hydrogen gas (at pressures from 70 to 105 bar) to velocities in the range 1.0–1.5 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 eight-shot injection system has been installed and operated on TFTR. The design features, operation, and performance characteristics of the system are described.
Original language | English |
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Pages (from-to) | 1195-1203 |
Number of pages | 9 |
Journal | Review of Scientific Instruments |
Volume | 58 |
Issue number | 7 |
DOIs | |
State | Published - 1987 |
Keywords
- CRYOGENICS
- DATA ACQUISITION SYSTEMS
- DESIGN
- DEUTERIUM
- FUEL PELLETS
- HYDROGEN
- OPERATION
- ORNL
- PELLET INJECTION
- PERFORMANCE
- PNEUMATICS
- REACTOR FUELING
- TFTR TOKAMAK