Precise values for radiated power during mitigated disruptions are important for predicting the effectiveness of mitigation techniques at preventing damage to future large or high-field tokamaks like ITER and SPARC. Scarcity of diagnostics optimized for disruption radiated power studies forces reducing the dimensionality of the problem when using conventional methods. Plasma radiation during the thermal quench is highly toroidally and poloidally asymmetric and the inferred radiated power is sensitive to the structure. Emis3D is a new approach to resolving the 3D radiation structure from limited diagnostics. It leverages the Cherab modeling framework to generate synthetic measurements of feed forward emissivity models. The underdetermined problem is then addressed by evaluating many possible models to find the group of best-fit solutions, providing a more informed range of possible radiated powers and peaking factors than conventional methods. Discharges from the JET Shattered Pellet Injection database are analyzed using Emis3D and compared with conventional methods. Future work will explore the radiation intensity on individual plasma-facing components in JET. Emis3D also interfaces with 3D MHD codes to better facilitate comparisons of simulation and experiment.
Emis3D: Radiated Power Modeling Following Shattered Pellet Injection Mitigation in JET
Bonfiglio Daniele;
2021
Abstract
Precise values for radiated power during mitigated disruptions are important for predicting the effectiveness of mitigation techniques at preventing damage to future large or high-field tokamaks like ITER and SPARC. Scarcity of diagnostics optimized for disruption radiated power studies forces reducing the dimensionality of the problem when using conventional methods. Plasma radiation during the thermal quench is highly toroidally and poloidally asymmetric and the inferred radiated power is sensitive to the structure. Emis3D is a new approach to resolving the 3D radiation structure from limited diagnostics. It leverages the Cherab modeling framework to generate synthetic measurements of feed forward emissivity models. The underdetermined problem is then addressed by evaluating many possible models to find the group of best-fit solutions, providing a more informed range of possible radiated powers and peaking factors than conventional methods. Discharges from the JET Shattered Pellet Injection database are analyzed using Emis3D and compared with conventional methods. Future work will explore the radiation intensity on individual plasma-facing components in JET. Emis3D also interfaces with 3D MHD codes to better facilitate comparisons of simulation and experiment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
