Editing Enriched uranium (section)

===Other techniques===

====Aerodynamic processes====
[[File:Aerodynamic enrichment nozzle.svg|thumb|Schematic diagram of an aerodynamic nozzle. Many thousands of these small foils would be combined in an enrichment unit.]]
[[File:LIGA-Doppelumlenksystem.jpg|right|thumb| The X-ray-based [[LIGA]] manufacturing process was originally developed at the Forschungszentrum Karlsruhe, Germany, to produce nozzles for isotope enrichment.<ref name=Becker-1982>{{Cite journal | last1=Becker |first1=E. W. | last2=Ehrfeld | first2=W. | last3=Münchmeyer | first3=D. | last4=Betz | first4=H. | last5=Heuberger | first5=A. | last6=Pongratz | first6=S. | last7=Glashauser | first7=W. | last8=Michel | first8=H. J. | last9=Siemens | first9=R. | title=Production of Separation-Nozzle Systems for Uranium Enrichment by a Combination of X-Ray Lithography and Galvanoplastics | journal=Naturwissenschaften | volume=69 | pages=520–523 | year=1982 | doi=10.1007/BF00463495 | issue=11 | bibcode=1982NW.....69..520B | s2cid=44245091 }}</ref>]]
Aerodynamic enrichment processes include the Becker jet nozzle techniques developed by E. W. Becker and associates using the [[LIGA]] process and the [[vortex tube]] separation process. These [[aerodynamic]] separation processes depend upon diffusion driven by pressure gradients, as does the gas centrifuge. They in general have the disadvantage of requiring complex systems of cascading of individual separating elements to minimize energy consumption. In effect, aerodynamic processes can be considered as non-rotating centrifuges. Enhancement of the centrifugal forces is achieved by dilution of [[Uranium hexafluoride|UF<sub>6</sub>]] with [[hydrogen]] or [[helium]] as a carrier gas achieving a much higher flow velocity for the gas than could be obtained using pure uranium hexafluoride. The [[NECSA|Uranium Enrichment Corporation of South Africa]] (UCOR) developed and deployed the continuous Helikon vortex separation cascade for high production rate low-enrichment and the substantially different semi-batch Pelsakon low production rate high enrichment cascade both using a particular vortex tube separator design, and both embodied in industrial plant.<ref name="The Pelsakon Cascade for Uranium Enrichment">{{cite journal|last=Smith|first=Michael|author2=Jackson A G M|title=Dr|journal=South African Institution of Chemical Engineers – Conference 2000|year=2000|pages=280–289}}</ref> A demonstration plant was built in Brazil by NUCLEI, a consortium led by [[Industrias Nucleares do Brasil]] that used the separation nozzle process. All methods have high energy consumption and substantial requirements for removal of waste heat; none is currently still in use.

====Electromagnetic isotope separation====
{{Main|Calutron}}
[[File:Electromagnetic separation.svg|thumb|Schematic diagram of uranium isotope separation in a [[calutron]] shows how a strong magnetic field is used to redirect a stream of uranium ions to a target, resulting in a higher concentration of uranium-235 (represented here in dark blue) in the inner fringes of the stream.]]

In the [[electromagnetic isotope separation]] process (EMIS), metallic uranium is first vaporized, and then ionized to positively charged ions. The cations are then accelerated and subsequently deflected by magnetic fields onto their respective collection targets. A production-scale [[mass spectrometer]] named the [[calutron]] was developed during World War II that provided some of the <sup>235</sup>U used for the [[Little Boy]] nuclear bomb, which was dropped over [[Hiroshima]] in 1945. Properly the term 'calutron' applies to a multistage device arranged in a large oval around a powerful electromagnet. Electromagnetic isotope separation has been largely abandoned in favour of more effective methods.

====Chemical methods====
One chemical process has been demonstrated to pilot plant stage but not used for production. The French CHEMEX process exploited a very slight difference in the two isotopes' propensity to change [[Valence (chemistry)|valency]] in [[redox|oxidation/reduction]], using immiscible aqueous and organic phases. An ion-exchange process was developed by the [[Asahi Chemical Company]] in Japan that applies similar chemistry but effects separation on a proprietary resin [[ion-exchange]] column.

====Plasma separation====
Plasma separation process (PSP) describes a technique that makes use of [[superconducting magnet]]s and [[plasma physics]]. In this process, the principle of [[ion cyclotron resonance]] is used to selectively energize the <sup>235</sup>U isotope in a [[Plasma (physics)|plasma]] containing a mix of [[ion]]s. France developed its own version of PSP, which it called RCI. Funding for RCI was drastically reduced in 1986, and the program was suspended around 1990, although RCI is still used for stable isotope separation.