Operation of a repeating pneumatic hydrogen pellet injector on the Tokamak Fusion Test Reactor

Journal Article · Thu May 01 04:00:00 EDT 1986 · J. Vac. Sci. Technol., A; (United States)

DOI:https://doi.org/10.1116/1.573419· OSTI ID:5521037

Combs, S K; Milora, S L; Foust, C R; Schmidt, G L; McBride, T P

The repeating pneumatic hydrogen pellet injector, which was developed at the Oak Ridge National Laboratory (ORNL), has been installed and operated on the Tokamak Fusion Test Reactor (TFTR). The injector combines high-speed extruder and pneumatic acceleration technologies to propel frozen hydrogen isotope pellets repetitively at high speeds. The pellets are transported to the plasma in an injection line that also serves to minimize the gas loading on the torus; the injection line incorporates a fast shutter valve and 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. In early pellet fueling experiments on TFTR, the injector has been used to deliver deuterium pellets at speeds ranging from 1.0 to 1.5 km/s into plasma discharges. First, single large (nominal 4 mm diam) pellets provided high densities in TFTR (1.8 x 10/sup 14/ cm/sup -3/ on axis); after conversion to smaller (nominal 2.7 mm diam) pellets, up to five pellets were injected at 0.25 s intervals into a plasma discharge, giving a line-averaged density of 1 x 10/sup 14/ cm/sup -3/. Operating characteristics and performance of the injector in initial tests on TFTR are presented.

• Research Organization: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5521037
• Journal Information: J. Vac. Sci. Technol., A; (United States), Journal Name: J. Vac. Sci. Technol., A; (United States) Vol. 4:3; ISSN JVTAD
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700205* -- Fusion Power Plant Technology-- Fuel
Heating
& Injection Systems
CONTROL SYSTEMS
DATA ACQUISITION SYSTEMS
FUEL PELLETS
OPERATION
PELLET INJECTION
PELLETS
PERFORMANCE
REACTOR FUELING
TFTR TOKAMAK
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
VACUUM SYSTEMS
VELOCITY