The midplane electron separatrix density, ne,sep, in JET-ILW L-mode and H-mode low triangularity deuterium fuelled plasmas exhibits a strong explicit dependence on the averaged outer divertor target electron temperature, ne,sep ~ Te,ot-1\/2. This dependence is reproduced by analytic reversed two point model (rev-2PM), and arises from parallel pressure balance, as well as the ratio of the power and momentum volumetric loss factors, (1 – fcooling)\/(1 – fmom-loss). Quantifying the influence of the (1 – fcooling) and (1 – fmom-loss) loss factors on ne,sep has been enabled by measurement estimates of these quantities from L-mode density (fueling) ramps in the outer horizontal, VH(C), and vertical target, VV, divertor configurations. Rev-2PM ne,sep estimates from the extended H-mode and more limited L-mode datasets are recovered to within \u00b125% of the measurements, with a scaling factor applied to account for use of $leftlangle {{T_{{text{e,ot}}}}} rightrangle $, an averaged quantity, rather than flux tube resolved target values. Both the (1 – fcooling) and (1 – fmom-loss) trends and recovery of ne,sep using the rev-2PM formatting are reproduced in EDGE2D-EIRENE L-mode-like and H-mode-like density scan simulations. The general lack of a divertor configuration effect in the JET-ILW ne,sep trends can be attributed to a significant influence of main chamber recycling, which has been shown in the EDGE2D-EIRENE results to moderate ne,sep with respect to changes in divertor neutral leakage imposed by changes in the divertor configuration. The unified ne,sep vs $leftlangle {{T_{{text{e,ot}}}}} rightrangle $ trends can, however, be broken if large modifications to the divertor geometry (e.g. complete removal of the outer divertor baffle structure) are introduced in the model. The more pronounced high-field side high density region formation in the VH(C) configuration with reduced clearance to the separatrix does not appear to have a significant influence on the outer midplane separatrix and pedestal parameters when mapped to $leftlangle {{T_{{text{e,ot}}}}} rightrangle $, although conditions at the inner midplane could not be assessed.<\/p>\n","protected":false},"excerpt":{"rendered":"
Lomanowski B.; Rubino G.; Uccello A.; Dunne M.; Vianello N.; Aleiferis S.; Canik J.; Carvalho I.; Corrigan G.; Frassinetti L.; Frigione D.; Garzotti L.; Groth M.; Meigs A.; Maslov M.; Perez von Thun C.; Rimini F.; Schneider P.A.; Sergienko G.; Simpson J.; Van Eester D.<\/p>\n","protected":false},"featured_media":1294,"comment_status":"closed","ping_status":"open","template":"","meta":[],"product_cat":[574],"product_tag":[2291,4520,4521,4522],"class_list":["post-10454","product","type-product","status-publish","has-post-thumbnail","hentry","product_cat-journal-articles","product_tag-separatrix-density","product_tag-divertor-and-main-chamber-recycling","product_tag-two-point-model","product_tag-sol-pedestal-core-integration","prodpage-style2"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product\/10454","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=10454"}],"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=10454"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product_cat?post=10454"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.istp.cnr.it\/it\/wp-json\/wp\/v2\/product_tag?post=10454"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}