ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
Frozen pellets (H2, D2, and Ne at 8 K) of nominal 2.7 mm diam were shot through a coiled tube (single loop of (approximate)0.6 m diam and 8.5 mm bore), and the speed limit for survival was recorded for each pellet type. Intact H2 pellets were observed at speeds approaching 500 m/s; but neon pellets could not survive much more than 100 m/s. The speed limit for D2 pellets fell in the middle at (approximate)300 m/s. Some D2 pellets were also shot through a 30 m coiled tube consisting of 11 loops (average loop diameter of (approximate)0.8 m), and a speed limit of (approximate)100 m/s was observed. Injection of frozen H2 or D2 pellets is commonly used for core fueling of magnetically confined plasmas, and frozen neon pellets are sometimes used for impurity transport studies in similar experiments. The results from these tests add to a pellet database for injection lines with single- and complex multiple-curved guide tubes. All of the information to date suggests that frozen pellets can be delivered reliably from a pellet source to any accessible plasma location on a fusion device via "roller-coaster" tubes as long as the pellet speed is maintained below a threshold limit. © 2001 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1331322
