Editing Large Helical Device (section)

{{Infobox fusion devices
|name                 = LHD
|fullname             = Large Helical Device
|image                = Large Helical Device 2014.jpg
|imagetitle           = The Large Helical Device in 2014
|type                 = [[Heliotron]]
|city                 = [[Toki, Gifu|Toki]]
|state                = 
|country              = [[Japan]]
|coordinates          = <!-- {{coord|latitude|longitude|type:city|display=inline,title}} -->
|affiliation          = [[National Institutes of Natural Sciences, Japan|National Institute for Fusion Science]]
|major_radius         = {{cvt|3.9|m}}
|minor_radius         = {{cvt|0.6|m}}
|volume               = 
|field                = {{cvt|3.0|T}}
|heating              = 
|power                = 
|time                 = 
|current              = 
|construction_date    = 
|operation_start_year = 1998
|operation_end_year   = 
|ongoing              = yes
|prev                 = 
|next                 = 
|related              = 
|website              = <!-- {{url|insert here}} -->
|other_links          = 
}}
The {{Nihongo|'''Large Helical Device'''|大型ヘリカル装置|Ōgata Herikaru Sōchi}} ('''LHD''') is a fusion research device located in [[Toki, Gifu]], Japan. It is operated by the [[National Institutes of Natural Sciences, Japan|National Institute for Fusion Science]], and is the world's second-largest [[superconducting]] [[stellarator]], after [[Wendelstein 7-X]]. The LHD employs a [[heliotron]] [[magnetic field]] originally developed in Japan.

[[File:LHD plasma vacuum vessel.jpg|thumb|300px|An interior view of the vacuum vessel, which shows the LHD's superconducting coils.]]

The objective of the project is to conduct [[nuclear fusion|fusion]] [[Plasma (physics)|plasma]] confinement research in a steady state in order to elucidate possible solutions to physics and engineering problems in [[Helix|helical]] [[fusion power|plasma reactors]]. The LHD uses [[neutral beam injection]], ion cyclotron radio frequency (ICRF), and [[electron cyclotron resonance heating]] (ECRH) to heat the plasma, much like conventional [[tokamak]]s. The helical [[divertor]] heat and particle exhaust system uses the large helical coils to produce a diverting field. This configuration allows for the modification of the stochastic layer size, which is positioned between the confined plasma volume and the field lines that terminate on the divertor plate. Boundary plasma research at LHD focuses on the capability of the helical divertor as an exhaust system for heliotrons and stellarators.<ref>{{cite journal | last1 = Morisaki | first1 = T | last2 = Masuzaki | first2 = S | display-authors = 1 | title = Initial experiments towards edge plasma control with a closed helical divertor in LHD | journal = Nucl. Fusion | volume = 53 | pages = 063014 | date = 2013 | issue = 6 | url = https://iopscience.iop.org/article/10.1088/0029-5515/53/6/063014 | doi = 10.1088/0029-5515/53/6/063014 | bibcode = 2013NucFu..53f3014M | s2cid = 122537627 | url-access = subscription }}</ref><ref>{{cite web |url=https://www.jspf.or.jp/jspf_annual2018/JSPF35/pdf/S8-4.pdf  |title=Progress in Divertor and Edge Transport Research for Stellarator Plasmas |date=December 6, 2018 |first1=Aaron |last1=Bader |first2=Florian |last2=Effenberg|first3=Chris C. |last3=Hegna |archive-url=https://web.archive.org/web/20230726233025/www.jspf.or.jp/jspf_annual2018/JSPF35/pdf/S8-4.pdf |archive-date=2023-07-26}}</ref>