Sceptre (fusion reactor)

Sceptre (stabilized controlled pinch thermonuclear reactor experiment) was a series of early fusion power devices based on the Z-pinch concept of plasma confinement, built in the UK starting in 1956. They were the ultimate versions of a series of devices tracing their history to the original pinch machines, built at Imperial College London by Cousins and Ware in 1947. When the UK's fusion work was classified in 1950, Ware's team was moved to the Associated Electrical Industries (AEI) labs at the Atomic Weapons Establishment (AWE, Aldermaston).

The team worked on small linear tubes like the ones that were known to be used in the Soviet Union, but these demonstrated problems and work on these ended. They then turned their attention to the problems associated with using metal tubes with high voltages, in support of the efforts at Harwell. As part of this AEI built a 64-segment metal tube that could be connected together in various ways to conduct experiments.

Following this, they were eventually allowed to make several smaller toroidal devices, similar to those at Harwell, as purely experimental devices. When Harwell's ZETA machine emitted seeming fusion neutrons, AEI quickly built a smaller machine out of parts of the earlier metal-liner testbed, producing Sceptre III. Sceptre III also emitted neutrons, seeming to confirm the ZETA results. It was later found that the neutrons were spurious, and UK work on Z-pinch ended in the early 1960s.