Speaker
Description
Abstract:
During the DTE2 and DTE3 JET campaigns, efforts were made to develop a high-current baseline scenario [1]. Baseline plasmas were affected by impurities (primarily beryllium Be and tungsten W), which were localised on the low-field side of the device. Tomograms derived from bolometric measurements highlighted regions of high radiated emissivity at the periphery of the plasma. This radiation avoided the core from being poisoned by such impurities, which could otherwise lead to an abrupt termination of the discharge (disruption) or simply prevented high fusion performance from being achieved. Such sort of screening was ensured by maintaining a steady ELM regime [1]. This contribution presents an analysis of tomograms derived from bolometric measurements in order to estimate the radiated power and radiation density profiles of these highly emissive regions for a selected set of DTE3 pulses. Preliminary results show that emissivity peaks occur in these regions close to the top of the pedestal (i.e. around ψ~0.75 with respect to ψ~0.9), accounting for up to 78% and 71% of the radiated power from the core and total radiated power, respectively. Further efforts will be dedicated to an extended systematic analysis. This work is expected to be relevant for modelling purposes, considering the provided radiation density profiles as sinks, and could provide a feature for disruption mitigation studies.
Acknowledgements: This work has been carried out within the framework of the EUROfusion Consortium, funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 — EUROfusion). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the European Commission can be held responsible for them
References
[1] L. Garzotti et al., “Development of high-current baseline scenario for high deuterium–tritium fusion performance at JET”, Plasma Phys. Control. Fusion 67 (2025) 075011 (10pp)
