Repeating pneumatic hydrogen pellet injector for plasma fueling

Journal Article · Sat Jun 01 04:00:00 EDT 1985 · Rev. Sci. Instrum.; (United States)

DOI:https://doi.org/10.1063/1.1138025· OSTI ID:5733276

Combs, S K; Milora, S L; Foust, C R; Foster, C A; Schuresko, D D

A repeating pneumatic pellet injector has been developed for plasma fueling applications. The repetitive device extends pneumatic injector operation to steady state. The active mechanism consists of an extruder and a gun assembly that are cooled by flowing liquid-helium refrigerant. The extruder provides a continuous supply of solid hydrogen to the gun assembly, where a reciprocating gun barrel forms and chambers cylindrical pellet from the extrusion; pellets are then accelerated with compressed hydrogen gas (pressures up to 125 bar) to velocities < or =1.9 km/s (1.6 km/s for deuterium pellets). The gun assembly design can accommodate different pellet sizes and barrel lengths. Steady-state rates of 2 s/sup -1/ have been obtained with 2.1- , 3.4- , and 4.0-mm-diameter pellets. The present apparatus operates at higher firing rates in short bursts; for example, a rate of 6 s/sup -1/ for 2 s with the larger pellets. These pellet parameters are in the range applicable for fueling large present-day fusion devices such as the Tokamak Fusion Test Reactor (TFTR). Experimental results are presented, including effects of propellant pressure and barrel length on gun performance.

• Research Organization: Lawrence Livermore National Laboratory, University of California, P.O. Box 808, Livermore, California 94550
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5733276
• Journal Information: Rev. Sci. Instrum.; (United States), Journal Name: Rev. Sci. Instrum.; (United States) Vol. 56:6; ISSN RSINA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700205* -- Fusion Power Plant Technology-- Fuel
Heating
&amp; Injection Systems
FUEL PELLETS
FUEL SYSTEMS
PELLET INJECTION
PELLETS
REACTOR FUELING
TFTR REACTORS