Artículo
Expanding the role of impurity spectroscopy for investigating the physics of high-Z dissipative divertors
Autor/es | Reinke, M.L.
Meigs, A. Delabie, E. Mumgaard, R. Reimold, F. Jet Contributors García Muñoz, Manuel |
Departamento | Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear |
Fecha de publicación | 2017-08 |
Fecha de depósito | 2020-07-31 |
Publicado en |
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Resumen | New techniques that attempt to more fully exploit spectroscopic diagnostics in the divertor and pedestal region during highly dissipative scenarios are demonstrated using experimental results from recent low-Z seeding ... New techniques that attempt to more fully exploit spectroscopic diagnostics in the divertor and pedestal region during highly dissipative scenarios are demonstrated using experimental results from recent low-Z seeding experiments on Alcator C-Mod, JET and ASDEX Upgrade. To exhaust power at high parallel heat flux, q ‖ > 1 GW/m 2 , while minimizing erosion, reactors with solid, high-Z plasma facing components (PFCs) are expected to use extrinsic impurity seeding. Due to transport and atomic physics processes which impact impurity ionization balance, so-called ‘non-coronal’ effects, we do not accurately know and have yet to demonstrate the maximum q ‖ which can be mitigated in a tokamak. Radiation enhancement for nitrogen is shown to arise primarily from changes in Li- and Be-like charge states on open field lines, but also through transport-driven enhancement of H- and He-like charge states in the pedestal region. Measurements are presented from nitrogen seeded H-mode and L-mode plasmas where emission from N 1+ through N 6+ are observed. Active charge exchange spectroscopy of partially ionized low-Z impuri- ties in the plasma edge is explored to measure N 5+ and N 6+ within the confined plasma, while passive UV and visible spectroscopy is used to measure N 1+ -N 4+ in the boundary. Examples from recent JET and Alcator C-Mod experiments which employ nitrogen seeding highlight how improving spectroscopic cov- erage can be used to gain empirical insight and provide more data to validate boundary simulations. |
Identificador del proyecto | 633053 |
Cita | Reinke, M.L., Meigs, A., Delabie, E., Mumgaard, R., Reimold, F., Jet Contributors, y García Muñoz, M. (2017). Expanding the role of impurity spectroscopy for investigating the physics of high-Z dissipative divertors. Nuclear Materials and Energy, 12, 91-99. |
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