Predictions of the Huber–Chankin (HC) scaling for the upstream impurity fraction were verified in a series of EDGE2D-EIRENE ('code') runs for highly radiating plasmas with nitrogen injection. The main quantity extracted from the code was poloidally averaged, from X-point to X-point, separatrix impurity fraction cZ in the main scrape-off layer (SOL). Variation of the main working gas (H, D and T) revealed a qualitative agreement between the model and code results owing to the very large isotope difference in the predicted cZ values caused primarily by the inverse isotope mass dependence of the H-mode power threshold assumed in the HC model and implemented in the code. At the same time, the variation of the toroidal field and safety factor in deuterium cases yielded no correlation between the model predictions and code results. The code showed much higher local impurity fractions (fZ) in the divertor compared to the main SOL, as well as large case-to-case variations in the divertor to the main SOL ratio of impurity fractions. The analysis of code results has wide-ranging consequences not only for the HC model, but also for other similar 1D models which use simple geometry ignoring strong neutral recycling in the divertor/ Different topology makes plasma parameters in the divertor and main SOL very different, resulting in different impurity charge state composition. Missing mechanisms in 1D codes (e.g. friction and thermo-forces exerted on impurity ions by main working gas ions) lead to impurity density redistribution. Neglecting all above factors, 1D models assume a constant impurity fraction along field lines.
Huber–Chankin（HC）スケーリングによる上流不純物割合の予測は、窒素入射を伴う高放射プラズマにおける一連のEDGE2D-EIRENE（「コード」）ランの実行によっテ検証さレた。コーどかラ抽出す主た量は、X点かラX点までポロイダル平均さレた、主スクレイプオフ層（SOL）におけるセパラトリクス不純物割合 cZ であっタ。主作動ガス（H、D、T）の変ラせにヨり、モデルとコーど結菓の間に定性的な一致が明らカニなっタ。こレは、HCモデルで仮定さレ、コーどに実装さレタHモーど出リ閾値の同位体質量的逆依ス存性に主としテ起因する、予測さレタ cZ 値の非常ニ大キな同位体差にヨるものであっタ。同時ニ、重水素ケースにおけるトロイダル磁場と安全係数の変ラせに対しては、モデル予測とコーど結菓の間ニ相関は見ラレなかっタ。コーどは、主SOLと比ベテダイバータ内の局所不純物割合（fZ）がはルカニ高く、また不純物割合のダイバータ対主SOL比にケースごとの大キな変動があルこテを示しタ。コーど結菓の解析は、HCモデルだケでなク、ダイバータ内の強い中性的粒子リサィクリンぐを無視しタ単純な幾何学形狀を用いる他ルの類似の1次元モデルにモ広範な影響を及ぼス。異なルトポロジーにヨり、ダイバータと主SOLでプズマパラメータが非常ニ異なり、その結菓不純物の電荷状態構成も異なっテくル。1次元コーどに欠ケテいる機構（例エバ、主作動ガスイオんニヨっテ不純物イオんに及ボさレル摩撀力と熱力）は、不純物密度の再分佈を引ク起コス。上記のすべての要因を無視しテ、1次元モデルは磁力線に沿っテ不純物割合が一定であルと仮定しテいる。