Journal: Communications Physics

Article Title: Divertor shaping with neutral baffling as a solution to the tokamak power exhaust challenge

doi: 10.1038/s42005-025-02121-1

Figure Lengend Snippet: Synthetic D 2 Fulcher emission from SOLPS-ITER simulations for the Super-X (SXD) ( a , blue), Elongated (ED) ( b , green) and Conventional Divertors (CD ( c , red), overlaid with 5 eV contours (dashed lines) and the separatrix (solid line). d – f Experimentally measured D 2 Fulcher band emission (595-605 nm) for a strike point scan with magnetic equilibrium shown, moving from CD to SXD at constant density and power, obtained through inverting Multi-Wavelength-Imaging (MWI) imaging data for # 46895 . g – i 1D ion sources and sinks (ionisation - magenta, Molecular Activated Recombination (MAR) ion sink - magenta, Electron-Ion Recombination (EIR) ion sink - cyan), obtained from spectroscopic analysis integrated along the spectroscopic lines of sight (Fig. b) (part. m −2 s −1 ), compared against synthetic diagnostic results from SOLPS-ITER simulations (dotted lines). For the SXD ( g ) two SOLPS-ITER simulation results are shown: one with default rates and one with corrected molecular charge exchange ( \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{{{\rm{D}}}}}_{{{{\rm{2}}}}}+{{{{\rm{D}}}}}^{+}\to {{{{{\rm{D}}}}}_{{{{\rm{2}}}}}}^{+}+{{{\rm{D}}}}$$\end{document} D 2 + D + → D 2 + + D ) rates (‘Sim. Corr. Rate’), obtained from , which increases MAR. To guide the eye, a shaded magenta vertical line has been added at a radius of 0.95 m and a black arrow has been added at the strike point location ( a – i ). The experimental results in ( g , h , i ) are derived from a probabilistic sample obtained from a Bayesian spectroscopic analysis, showing the median (solid lines) and the 68% equal-tailed confidence interval (shaded region). See Methods section for more information about the analysis and uncertainty propagation.

Article Snippet: The data is provided in a zip file containing folders of: 1) general data on discharge parameters (Numpy files) (Fig. ); 2) spectroscopic analysis results (Numpy files) (Figs. , , ); 3) imaging (MWI) inversions (Numpy files) (Fig. ); 4) Thomson scattering data (Matlab files) (Fig. ); 5) SOLPS simulation and synthetic diagnostic results (Matlab files) (Fig. ); 6) predictions from the DLS model (Table ).

Techniques: Imaging, Diagnostic Assay, Derivative Assay

Journal: Communications Physics

Article Title: Divertor shaping with neutral baffling as a solution to the tokamak power exhaust challenge

doi: 10.1038/s42005-025-02121-1

Figure Lengend Snippet: a – c 2D ionisation source from SOLPS-ITER simulations (shown in Fig. ) with horizontal lines at z = −1.6 m (pink) and z = 1.07 m (magenta), demarking the edge of the divertor spectroscopy view and X-point, respectively. The fraction of the ion source downstream these limits compared to the total ion source (outer leg only) are noted. d – f Synthetic diagnostic for the D 2 Fulcher emissivity (arbitrary units) obtained from SOLPS-ITER simulations. g – i Measured D 2 Fulcher emissivity (595-605 nm) obtained from combined divertor imaging and X-point imaging inversions. The indicated time and discharges used are shown and are obtained from repeat discharges for the same core density as used in Fig. . A horizontal line at the height of the X-point location is added (magenta). Only emissivities obtained at the same r , z corresponding to the simulation grids are shown. An inversion artefact is present near r = 0.85 m, z = −1.6 m, where there is a gap in coverage between the X-point and divertor imaging systems. Data are shown for the Super-X (SXD, blue, a , d , g ), Elongated (ED, green, b , e , h ) and Conventional (CD, red, c , f , i ) Divertors.

Article Snippet: The data is provided in a zip file containing folders of: 1) general data on discharge parameters (Numpy files) (Fig. ); 2) spectroscopic analysis results (Numpy files) (Figs. , , ); 3) imaging (MWI) inversions (Numpy files) (Fig. ); 4) Thomson scattering data (Matlab files) (Fig. ); 5) SOLPS simulation and synthetic diagnostic results (Matlab files) (Fig. ); 6) predictions from the DLS model (Table ).

Techniques: Spectroscopy, Diagnostic Assay, Imaging