Mega Ampere Spherical Tokamak

Coordinates: 51°39′33″N 1°13′50″W / 51.65917°N 1.23056°W / 51.65917; -1.23056 Coordinates: 51°39′33″N 1°13′50″W / 51.65917°N 1.23056°W / 51.65917; -1.23056 The Mega Ampere Spherical Tokamak (MAST) experiment was a nuclear fusion experiment in operation at Culham Centre for Fusion Energy, Oxfordshire, England, from December 1999 to September 2013. It followed the highly successful Small Tight Aspect Ratio Tokamak (START) experiment (1991-1998) and is followed by MAST-Upgrade (2016 - ), which re-uses many of MAST's components and services. MAST used the same innovative spherical tokamak design as START, which has shown itself to be more efficient than the conventional toroidal design, adopted by Joint European Torus (JET) and ITER. START proved to exceed even the most optimistic predictions and the purpose of MAST is to confirm the results of its forerunner by using a larger more purpose-built experiment. It was fully commissioned by EURATOM/UKAEA and took two years to design and a further two years to construct. It includes a neutral beam injector similar to that used on START and uses the same merging compression technique instead of the conventional direct induction. Merging compression provides a valuable saving of central solenoid flux, which can then be used to further ramp up the plasma current and/or maintain the required current flat-top. Its plasma volume is about 8 m3. It confined plasmas with densities on the order of 1020/m3.