Editing Super-Kamiokande (section)

==Description==
Super-K is located {{Convert|1000|m|ft|-2|abbr=on}} underground in the Mozumi [[mining|Mine]] in Hida's Kamioka area.<ref name=":3">{{cite web |title=Physicists Go Deep in Search of Dark Matter |website=[[Scientific American]] |url=https://www.scientificamerican.com/article/physicists-go-deep-in-search-of-dark-matter/}}</ref><ref name=":4">{{cite web |title=The Super-Kamiokande detector awaits neutrinos from a supernova |url=https://phys.org/news/2016-11-super-kamiokande-detector-awaits-neutrinos-supernova.html}}</ref> It consists of a cylindrical stainless steel tank that is {{Convert|41.4|m|ft|0|abbr=on}} tall and {{Convert|39.3|m|ft|0|abbr=on}} in diameter holding 50,220 tonnes (55,360 US tons) of [[ultrapure water]]. The tank volume is divided by a stainless steel superstructure into an inner detector (ID) region, which is {{Convert|36.2|m|ft|0|abbr=on}} in height and {{Convert|33.8|m|ft|0|abbr=on}} in diameter, and outer detector (OD) which consists of the remaining tank volume. Mounted on the superstructure are 11,146 [[photomultiplier tube]]s (PMT) {{Convert|50|cm|0|abbr=on}} in diameter that face the ID and 1,885 {{Convert|20|cm|0|abbr=on}} PMTs that face the OD. A [[Tyvek]] and blacksheet barrier attached to the superstructure optically separates the ID and OD.{{citation needed|date=April 2020}}

A neutrino interaction with the [[electron]]s or nuclei of water can produce a charged particle that moves faster than the [[speed of light#Propagation of light|speed of light in water]], which is slower than the [[speed of light in vacuum]]. This creates a cone of light known as [[Cherenkov radiation]], which is the optical equivalent to a [[sonic boom]]. The Cherenkov light is projected as a ring on the wall of the detector and recorded by the PMTs. Using the timing and charge information recorded by each PMT, the interaction vertex, ring direction, and flavor of the incoming neutrino is determined. From the sharpness of the edge of the ring the type of particle can be inferred. The [[scattering|multiple scattering]] of electrons is large, so electromagnetic showers produce fuzzy rings. Highly [[special relativity|relativistic]] [[muon]]s, in contrast, travel almost straight through the detector and produce rings with sharp edges.{{citation needed|date=April 2020}}