Low aspect ratio tokamaks may provide a low cost route to developing magnetic fusion energy and may offer simpler and more economic fusion reactors. The first test of this concept with hot plasmas has been conducted with the Small Tight Aspect Ratio Tokamak (START) experiment now in operation at Culham Laboratory. The novel method of plasma formation is described and observations of plasmas at aspect ratios as low as 1.3 are presented, indicating high temperature discharges with good global stability properties and typical tokamak characteristics. This represents a new and significant extension of the parameter range of the conventional tokamak
Behaviour of low-aspect-ratio tokamak plasmas