Editing Fusion power (section)

=== Magnetic or electric pinches ===
{{Main|Pinch (plasma physics)}}

* ''[[Z-pinch]]:'' A current travels in the z-direction through the plasma. The current generates a magnetic field that compresses the plasma. Pinches were the first method for human-made controlled fusion.<ref name="Seife, Charles 2008">{{cite book |last=Seife |first=Charles |title=Sun in a bottle: the strange history of fusion and the science of wishful thinking |publisher=Viking |year=2008 |isbn=978-0670020331 |location=New York |language=en-us |oclc=213765956}}</ref><ref name="Phillips, James 2013">{{cite journal|last=Phillips|first=James|title=Magnetic Fusion|journal=Los Alamos Science|date=1983|pages=64–67|access-date=April 4, 2013|url=https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-83-5080|archive-url=https://web.archive.org/web/20161223163131/http://permalink.lanl.gov/object/tr?what=info%3Alanl-repo%2Flareport%2FLA-UR-83-5080|archive-date=December 23, 2016|url-status=dead}}</ref> The z-pinch has inherent instabilities that limit its compression and heating to values too low for practical fusion. The largest such machine, the UK's [[ZETA (fusion reactor)|ZETA]], was the last major experiment of the sort. The problems in z-pinch led to the tokamak design. The [[dense plasma focus]] is a possibly superior variation.
* ''[[Theta-pinch]]:'' A current circles around the outside of a plasma column, in the theta direction. This induces a magnetic field running down the center of the plasma, as opposed to around it. The early theta-pinch device Scylla was the first to conclusively demonstrate fusion, but later work demonstrated it had inherent limits that made it uninteresting for power production.
* ''Sheared Flow Stabilized Z-Pinch:'' Research at the [[University of Washington]] under Uri Shumlak investigated the use of sheared-flow stabilization to smooth out the instabilities of Z-pinch reactors. This involves accelerating neutral gas along the axis of the pinch. Experimental machines included the FuZE and Zap Flow Z-Pinch experimental reactors.<ref>{{Cite web|date=November 7, 2014|title=Flow Z-Pinch Experiments|url=https://www.aa.washington.edu/research/ZaP|access-date=October 11, 2020|website=Aeronautics and Astronautics|language=en}}</ref> In 2017, British technology investor and entrepreneur [[Benj Conway]], together with physicists Brian Nelson and Uri Shumlak, co-founded Zap Energy to attempt to commercialize the technology for power production.<ref>{{cite web |url=https://www.zapenergyinc.com/ |publisher=Zap Energy |title=Zap Energy |access-date=February 13, 2020 |archive-url=https://web.archive.org/web/20200213065735/https://www.zapenergyinc.com/ |archive-date=February 13, 2020 |url-status=dead }}</ref><ref>{{Cite web|title=Board of Directors|url=https://www.zapenergyinc.com/board|access-date=September 8, 2020|website=ZAP ENERGY|language=en-US}}</ref><ref>{{Cite web|date=August 13, 2020|title=Chevron announces investment in nuclear fusion start-up Zap Energy|url=https://www.power-technology.com/news/chevron-announces-investment-nuclear-fusion-start-up-company-zap-energy/|access-date=September 8, 2020|website=Power Technology {{!}} Energy News and Market Analysis|language=en-GB}}</ref>
* ''Screw Pinch:'' This method combines a theta and z-pinch for improved stabilization.<ref>{{cite journal | last1=Srivastava | first1=Krishna M. | last2=Vyas | first2=D. N. | title=Non-linear analysis of the stability of the Screw Pinch | journal=Astrophysics and Space Science | publisher=Springer Nature | volume=86 | issue=1 | year=1982 | issn=0004-640X | doi=10.1007/bf00651831 | pages=71–89| bibcode=1982Ap&SS..86...71S | s2cid=121575638 }}</ref>