TOSCA nuclear fusion device; vacuum vessel and coils. Manufactured 1974. (TOkamak Shaping and Compression Assembly)

The small doughnut shaped tokamak reactor on display in the Technology Futures exhibition is called Tosca. Tokamak comes from the Russian for ‘torodial magnetic chamber’ (toroid-kamara-magnit-katushka). It was built in 1974 at the Culham Science Centre of the Atomic Energy Authority to study ways of improving the efficiency of the magnetic field used to keep the plasma confined in the doughnut ring. (See the section called ‘The fusion reactor’ for more details) This efficiency is key to make the fusion process a viable economic prospect as a future energy source. Tosca also had a means of studying plasma with non-circular cross sections. Results from Tosca influenced the design of JET. Tosca is especially important for the Science Museum's collections since it is one of the few tokamak devices small enough to be collected and displayed as a complete object.