The fully non-inductive sustainment of high normalized beta plasmas (betaN) is a crucial challenge for the steady-state operation of a tokamak reactor. In order to assess the difficulties facing such scenarios, steady-state regimes have been explored on the tokamak \u00e0 configuration variable (TCV) using the newly available 1 MW neutral beam injection (NBI) system. The operating space is extended towards plasmas that are closer to those expected in JT-60SA and ITER, i.e. with significant NBI and electron cyclotron resonance heating and current drive (ECRH\/CD), bootstrap current and fast ion (FI) fraction. BetaN values up to 1.4 and 1.7 are obtained in lower single null L-mode (H98(y,2)~0.8) and H-mode (H98(y,2)~1) plasmas, respectively, at zero time averaged loop voltage and q95~6. Fully non-inductive operation is not achieved with NBI alone, whose injection can even increase the loop voltage in the presence of EC waves. A strong contribution to the total plasma pressure of thermal and FIs from NBI is experimentally evidenced and confirmed by interpretative ASTRA and NUBEAM modeling, which further predicts that FI charge-exchange reactions are the main loss channel for NBH\/CD efficiency. Internal transport barriers, which are expected to maximize the bootstrap current fraction, are not formed in either the electron or the ion channel in the plasmas explored to date, despite a significant increase in the toroidal rotation and FI fraction with NBI, which are known to reduce turbulence. First results on scenario development of high-betaN fully non-inductive H-mode plasmas are also presented.<\/p>\n","protected":false},"excerpt":{"rendered":"
Piron C.; Garcia J.; Agostini M.; Fontana M.; Giruzzi G.; Gobbin M.; Goodman T.P.; Karpushov A.N.; Kong M.; Merle A.; Morales J.; Nowak S.; Pigatto L.; Sauter O.; Testa D.; Vallar M.; Yoshida M.<\/p>\n","protected":false},"featured_media":1294,"comment_status":"closed","ping_status":"open","template":"","meta":[],"product_cat":[574],"product_tag":[895,901,902],"class_list":["post-6554","product","type-product","status-publish","has-post-thumbnail","hentry","product_cat-journal-articles","product_tag-tokamak","product_tag-steady-state","product_tag-high-beta-n","prodpage-style2"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product\/6554","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/comments?post=6554"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/media\/1294"}],"wp:attachment":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/media?parent=6554"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product_cat?post=6554"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product_tag?post=6554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}