Pneumatic hydrogen pellet injection system for the ISX tokamak

1 April 1979

journal article
Published by AIP Publishing in Review of Scientific Instruments

Vol. 50 (4) , 482-487
https://doi.org/10.1063/1.1135856

Abstract

We describe the design and operation of the solid hydrogen pellet injection system used in plasma refueling experiments on the ISX tokamak. The gun-type injector operates on the principle of gas dynamic acceleration of cold pellets confined laterally in a tube. The device is cooled by flowing liquid helium refrigerant, and pellets are formed in situ. Room temperature helium gas at moderate pressure is used as the propellant. The prototype device injected single hydrogen pellets into the tokamak discharge at a nominal 330 m/s. The tokamak plasma fuel content was observed to increase by (0.5-1.2) x10(19) particles subsequent to pellet injection. A simple modification to the existing design has extended the performance to 1000 m/s. At higher propellant operating pressures (28 bars), the muzzle velocity is 20% less than predicted by an idealized constant area expansion process.

Keywords

This publication has 3 references indexed in Scilit:

Solid hydrogen pellet injection into the Ormak tokamak
Nuclear Fusion, 1977
Apparatus for producing uniform solid spheres of hydrogen
Review of Scientific Instruments, 1977
On the grain size of thin electroless permalloy films
Physica Status Solidi (a), 1972