@misc{oai:repo.qst.go.jp:00066928,
 author = {Obrejan, Kevin and 井戸村, 泰宏 and 本多, 充 and 井戸村 泰宏 and 本多 充},
 month = {Sep},
 note = {The use of tungsten to coat divertors or other plasma facing components, as will be the case for ITER, inevitably leads to the pollution of the fusion plasma by heavy and highly charged impurities. Several tokamaks (ASDEX Upgrade, JET) have reported on-axis accumulation of tungsten - which would be detrimental to fusion efficiency - and its exhaust by electron heating. This kind of neoclassical and turbulent transport of high-Z impurities is not yet fully understood. To treat high-Z impurities, the gyrokinetic full-f Eulerian simulation code GT5D was recently upgraded with an implicit collision solver based on a multi-species linear Fokker-Plank collision operator [Sugama, POP09], and a prior neoclassical benchmark for bulk ions between GT5D [Idomura, JCP16] and the Hirschman-Sigmar (HS) theory [Hirshiman, NF81] was extended to tungsten, further into the Pfirsch-Schluter (PS) transport regime. While a standard low order approximation of the HS theory [Kikuchi, PPCF95] showed a good agreement in the case of small temperature gradients, the cases of steep temperature profiles gave large differences. Instead, under such conditions, we tested an improved HS theory [Honda, POP14], that takes into account higher order flows to more accurately recover the friction coefficients in the PS regime, showing good agreement with GT5D., プラズマシミュレータシンポジウム2018},
 title = {Numerical study of impurity transport using the code GT5D},
 year = {2018}
}