2026.05.22

核融合科学研究所（NIFS）プラズマ量子プロセス（PQP）ユニットでは、ユニットの研究活動を広く発信していくために、セミナーを開催しております。今回は、講師として Institute of Plasma Physics and Laser Microfusion (Poland)の Łukasz Syrocki教授をお招きし、「Quantitative Analysis of Tungsten Impurities and Zeff in W7-X Plasmas Using Spectroscopic Methods and Spectral Modeling」と題してご講演いただきます。

【実施要項】

題目：Quantitative Analysis of Tungsten Impurities and Zeff in W7-X Plasmas Using Spectroscopic Methods and Spectral Modeling

講師：Łukasz Syrocki 教授（Institute of Plasma Physics and Laser Microfusion, Poland）

日時：2026年6月19日（金）

　　　13:00-14:00 （ハイブリッド開催）

会場：核融合科学研究所 研究１期棟5階501号室 および Zoom

＊Zoomアドレスについては、お問い合わせください。

【概要】

A soft X-ray pulse height analysis (PHA) system is routinely employed in various fusion devices, including tokamaks and stellarators such as Wendelstein 7-X (W7-X). The PHA system is a diagnostic tool that provides information on impurity content and electron temperature in the plasma. Additionally, it facilitates the estimation of the average effective charge (Zeff) by comparing experimental spectra with theoretical predictions. Interpreting experimental X-ray spectra in terms of key plasma parameters requires the identification and inclusion of all relevant factors influencing the spectrum in theoretical radiation models. Therefore, for this purpose, two theoretical models were utilized: the SimXRay code, which simulates soft X-ray spectra for different plasma scenarios; and the Flexible Atomic Code (FAC), which calculates a broad range of atomic properties, including energy levels, transition probabilities for radiative transitions and autoionization, cross-sections for excitation and ionization by electron impact, and other parameters necessary for the collisional–radiative approximation. Selected signals recorded during the OP1.2b and OP2.1 W7-X experimental campaigns were analyzed to achieve agreement between observed and simulated spectra. This comparison enabled a reliable interpretation of the experimental X-ray spectra and provided detailed information about the impurity content within the plasma.

【連絡先】

鈴木千尋（csuzuki (at) nifs.ac.jp）

※ (at) を＠に直してください。