@Sheep_Overboard Sir Mark Oliphant: “was engaged on two vital wartime projects: radar and the atom bomb.

The first #radar installations, which used long wavelengths (10 metres or more) to detect enemy aeroplanes, lacked precision and the equipment was too cumbersome to carry in an aircraft; an operating wavelength of 10 centimetres became the target. He laboured to improve the klystron—the thermionic valve which was thought to be the key—but more development was needed.

With Oliphant’s enthusiastic support, his Birmingham colleague #JohnRandall and a research student, #HenryBoot, developed the cavity magnetron, a valve that produced an extraordinary 10 kilowatts of #microwave power at 10 centimetres wavelength. This led to the birth of #AirborneRadar and the development of the much-improved radar systems that played a crucial role in the #Allied victory.”

#MarkOliphant / #Adelaide / #Australia <https://adb.anu.edu.au/biography/oliphant-sir-marcus-laurence-mark-782> the technical details behind the story:

“Nowhere in the world in 1939 was there a working, #pulsed, #cavity #magnetron capable of generating 10 kW or more peak power at wavelengths of 10 cm or less, which had a compact portable size, used a small permanent magnet and which was readily capable of being manufactured at scale. This was the design breakthrough achieved at #BirminghamUniversity.”

<https://ethw.org/Milestones:Development_of_the_Cavity_Magnetron,_1939-1941>