Supersonic Gas Injection Fuelling in Tokamaks

Abstract

Fusion power or the requirements for more energy to be created than is put in, relied on the triple product of
three vital quantities temperature (T), density (n) and confinement time (τ), (nτT) according to Lawson’s criterion. To
increase the plasma density Gas Puffing and Pellet injection methods have been significantly studied and compared in
regards of their efficiency, cost and complexity. Supersonic Gas Injection method gives high-speed and high-directive
gas deeper into the core plasma injection because of higher plenum pressure compared to the conventional gas puffing
and it can inject neutral particles. It is economical to develop and to maintain. This method has been tested around the
world in many fusion reactor tokamaks by researchers for example, NSTX, Tore Supra, KSTAR, HL-1M, ADITYA, etc.
After reviewing many experiments on all these tokamaks we have concluded that Supersonic molecular beam injection
(SMBI) is suitable for small and medium sized tokamaks for plasma fuelling.