Description du projet
Améliorer la précision des mesures de température dans les dispositifs de fusion
La fusion se produit lorsque la matière est portée à des températures extrêmement élevées et que des particules très énergétiques entrent en collision. Les dispositifs de fusion permettent de réaliser des expériences scientifiques fondamentales et pourraient également produire d’énormes quantités d’énergie sans émissions. Il en existe actuellement plus de 130 à l’échelle mondiale, qui sont actuellement en phase de planification et d’exploitation. La garantie d’une puissance élevée et d’une exploitation sûre repose, en partie, sur des caméras infrarouges pour surveiller et contrôler les composants en contact avec le plasma, mais il est difficile d’obtenir des mesures précises de la température. Soutenu par le programme Actions Marie Skłodowska-Curie, le projet MAGRITTE développera un jumeau numérique de la machine ainsi qu’un algorithme d’optimisation, comparant les images réelles aux images prédites afin de déterminer la température réelle lorsque les images produites correspondent.
Objectif
Infrared (IR) cameras are key diagnostics to monitor and control plasma-facing components (PFCs) in fusion devices. Nevertheless, the use of all-metallic PFCs with low and variable emissivity (ε ~ 0.1-0.5) makes it difficult to obtain a correct surface temperature measurement. The radiance collected by the IR camera includes both the thermal radiation emitted by the target and parasitic radiation coming from the target's surroundings. Furthermore, target emissivity changes with the surface temperature and roughness. This causes significant errors in the surface temperature measurement that we need to address for achieving high power and safe plasma operation. Inaccurate interpretation of IR temperature measurement could endanger machine safety (temperature underestimation) or on the contrary, lead to unnecessary pulse interruptions that reduce the overall performance of the machine (temperature overestimation). The current approach is to convert the radiance collected by each pixel in an apparent using a physical relationship between emitted radiance and temperature (Planck’s law). Because a portion of the collected radiance is due to reflection on the target, a systematic error is made. This method is unable to recover the portion of reflected radiance and to deduce the correct temperature of the target using only the emitted radiance. The proposed technique in this project is to use a digital twin of the machine and to make in it assumptions on the temperatures of the different elements of the machine in order to simulate the images that would be measured under these supposed conditions. By comparing to the real image measured by the camera and using optimization techniques, the assumptions on the parameters can be updated until the simulated and measured images are close enough. It is then deduced that the assumptions made on the parameters of the digital twin are correct and that they correspond to the real temperatures in the machine.
Champ scientifique
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Régime de financement
HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European FellowshipsCoordinateur
1000 Ljubljana
Slovénie