A New Four-Barrel Pellet Injection System for the TJ-II Stellarator

Conference · Sat Jan 01 00:00:00 EST 2011

OSTI ID:1110843

Combs, Stephen Kirk ^[1]; Foust, Charles R ^[1]; McGill, James M ^[1]; Baylor, Larry R ^[1]; Caughman, John B ^[1]; Fehling, Dan T ^[1]; Harris, Jeffrey H ^[1]; Meitner, Steven J ^[1]; Rasmussen, David A ^[1]; McCarthy, K. J. ^[2]; Chamorro, M. ^[3]; Garcia, R. ^[3]; Hildago, C. ^[3]; Medrano, M. ^[3]; Unamuno, R. ^[3]

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1. ORNL
2. EURATOM-CIEMAT, Madrid, Spain
3. Laboratory Nacional de Fusion, Madrid, Spain

A new pellet injection system for the TJ-II stellarator has been developed/constructed as part of a collaboration between the Oak Ridge National Laboratory (ORNL) and the Centro de Investigaciones Energ ticas, Medioambientales y Tecnol gicas (CIEMAT). ORNL is providing most of the injector hardware and instrumentation, the pellet diagnostics, and the pellet transport tubes; CIEMAT is responsible for the injector stand/interface to the stellarator, cryogenic refrigerator, vacuum pumps/ballast volumes, gas manifolds, remote operations, plasma diagnostics, and data acquisition. The pellet injector design is an upgraded version of that used for the ORNL injector installed on the Madison Symmetric Torus (MST). It is a four-barrel system equipped with a cryogenic refrigerator for in situ hydrogen pellet formation and a combined mechanical punch/propellant valve system for pellet acceleration (speeds ~100 to 1000 m/s). On TJ-II, it will be used as an active diagnostic and for fueling. To accommodate the plasma experiments planned for TJ-II, pellet sizes significantly smaller than those typically used for the MST application are required. The system will initially be equipped with four different pellet sizes, with the gun barrel bores ranging between ~0.5 to 1.0 mm. The new system is almost complete and is described briefly here, highlighting the new features added since the original MST injector was constructed. Also, the future installation on TJ-II is reviewed.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1110843
• Resource Relation: Conference: 38th IEEE International Conference on Plasmas Science (ICOPS) and 24th Symposium on Fusion Engineering (SOFE), Chicago, IL, USA, 20110626, 20110630
• Country of Publication: United States
• Language: English

Related Subjects

Pellet injector
TJ-II
hydrogen plasma
fueling
diagnostic