{"id":3120,"date":"2018-08-20T14:00:15","date_gmt":"2018-08-20T12:00:15","guid":{"rendered":"http:\/\/fusion.bsc.es\/?p=3120"},"modified":"2018-08-21T12:31:26","modified_gmt":"2018-08-21T10:31:26","slug":"evidence-of-generation-of-non-inductive-toroidal-plasma-current-above-density-limit","status":"publish","type":"post","link":"https:\/\/fusion.bsc.es\/index.php\/2018\/08\/20\/evidence-of-generation-of-non-inductive-toroidal-plasma-current-above-density-limit\/","title":{"rendered":"Evidence of generation of non-inductive toroidal plasma current above density limit"},"content":{"rendered":"<figure id=\"attachment_3124\" aria-describedby=\"caption-attachment-3124\" style=\"width: 740px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3124\" src=\"http:\/\/fusion.bsc.es\/wp-content\/uploads\/Alcator_C-Mod_Fisheye_from_Fport-e1534847392427.jpg\" alt=\"\" width=\"750\" height=\"384\" srcset=\"https:\/\/fusion.bsc.es\/wp-content\/uploads\/Alcator_C-Mod_Fisheye_from_Fport-e1534847392427.jpg 597w, https:\/\/fusion.bsc.es\/wp-content\/uploads\/Alcator_C-Mod_Fisheye_from_Fport-e1534847392427-400x205.jpg 400w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><figcaption id=\"caption-attachment-3124\" class=\"wp-caption-text\">Alcator C-Mod (Photo: Courtesy of MIT)<\/figcaption><\/figure>\n<p align=\"justify\">One of the key requirements to achieve <strong>steady-state power production<\/strong> in a fusion reactor based on the so-called <a href=\"https:\/\/en.wikipedia.org\/wiki\/Tokamak\">tokamak<\/a> configuration is to <strong>generate non-inductive toroidal plasma current<\/strong> in an efficient way. A recent paper published in <a href=\"https:\/\/journals.aps.org\/prl\/\">Physical Review Letters<\/a> entitled <strong>\u201c<em>Observation of Efficient Lower Hybrid Current Drive at High Density in Diverted Plasmas on the Alcator C-Mod Tokamak<\/em>\u201d<\/strong> reports on the use of <strong>lower hybrid current drive<\/strong> (LHCD) as an efficient mean to obtain non-inductive plasma current at high plasma densities in a diverted tokamak configuration such as <a href=\"https:\/\/www.psfc.mit.edu\/news\/topic\/alcator-c-mod-tokamak\">Alcator C-Mod<\/a>.<!--more--><\/p>\n<p align=\"justify\">As explained in the paper, \u201c<em>one of the biggest challenges since the beginning of the LHCD experiments in the 1970s has been to understand and overcome the so-called LHCD density limit-an anomalous loss of efficiency observed at a density below the classical wave accessibility limit<\/em>\u201d. The paper shows for the first time <strong>evidence of efficient generation of non-inductive current above the LH density limit n<sub>e<\/sub> = 1 x 10<sup>20<\/sup>m<sup>-3<\/sup><\/strong> in Alcator C-Mod. This has been achieved by increasing the toroidal plasma current up to 1.4MA and keeping n<sub>e<\/sub>\/n<sub>G<\/sub> &lt; 0.2. Furthermore, the paper recognizes the dependence of the scrape-off layer (SOL) parameters on the Greenwald density fraction as a relevant player to obtain efficient LHCD above the LH density limit.<\/p>\n<p align=\"justify\">For further information the paper can be downloaded at the PRL webpage <a href=\"https:\/\/journals.aps.org\/prl\/abstract\/10.1103\/PhysRevLett.121.055001\">here<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>One of the key requirements to achieve steady-state power production in a fusion reactor based on the so-called tokamak configuration is to generate non-inductive toroidal plasma current in an efficient way. A recent paper published in Physical Review Letters entitled \u201cObservation of Efficient Lower Hybrid Current Drive at High Density in Diverted Plasmas on the &#8230; <a title=\"Evidence of generation of non-inductive toroidal plasma current above density limit\" class=\"read-more\" href=\"https:\/\/fusion.bsc.es\/index.php\/2018\/08\/20\/evidence-of-generation-of-non-inductive-toroidal-plasma-current-above-density-limit\/\" aria-label=\"Read more about Evidence of generation of non-inductive toroidal plasma current above density limit\">Read more<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,6],"tags":[],"class_list":["post-3120","post","type-post","status-publish","format-standard","hentry","category-news","category-world"],"_links":{"self":[{"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/posts\/3120","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/comments?post=3120"}],"version-history":[{"count":10,"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/posts\/3120\/revisions"}],"predecessor-version":[{"id":3135,"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/posts\/3120\/revisions\/3135"}],"wp:attachment":[{"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/media?parent=3120"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/categories?post=3120"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fusion.bsc.es\/index.php\/wp-json\/wp\/v2\/tags?post=3120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}