Paul Dirac thought of the idea for isotope separation and tried creating such a device in 1934 in the lab of Peter Kapitza at Cambridge.
The Uranium Enrichment Corporation of South Africa, Ltd. (UCOR) developed the process, operating a facility at Pelindaba (known as the 'Y' plant) to produce hundreds of kilograms of HEU.
[2]: 103 In the vortex separation process a mixture of uranium hexafluoride gas and hydrogen is injected tangentially into a tube at one end through nozzles or holes, at velocities close to the speed of sound.
The spiral swirling flow decays downstream of the feed inlet due to friction at the tube wall.
A typical Helikon module consists of a large cylindrical steel vessel housing the 20 separator assemblies, along with two compressors (one mounted on each end), and two water-cooled heat exchangers.