Windscale Piles for processing in January 1952, and Tom Tuohy retrieved the first sample of British plutonium on 28 March 1952. Enough Windscale plutonium for an atomic bomb was delivered to the weapons division at Aldermaston in August, and Britain's first nuclear device was successfully detonated in the Operation Hurricane test in the Monte Bello Islands in Western Australia on 3 October 1952. Wigner energy, if allowed to accumulate, could escape spontaneously in a powerful rush of heat. On 7 May 1952, Pile No. 2 experienced a mysterious rise in core temperature despite the fact that the pile had been shut down.
Radar, Anti-Aircraft No. 3 Mk. 7 ten years off suggested no major production should take place, as developments in the interim would render any radars built in that period obsolete. However, various events in 1949, notably the first Soviet atomic test, led to sweeping upgrades, including the first contract for production Mk. 7's. These began to arrive in 1952. The Swiss Air Force received twelve Mk. 7's in 1958, which they referred to as Feuerleitradar ("fire control radar") Mark VII. They combined them with their own predictor, the Hasler-built "Kommandogerät" ("command device") 43/50R. Like its British counterpart, the 43/50R could be fed information directly from the