Using more eyes to control fusion reactions: EUROfusion granted a project on multivariable feedback control of radiative loss processes. After having published recently on the heat loss control using a single camera of the MANTIS system (link), a consortium led by DIFFER and EPFL has now scored a crucial follow-up research project in the EUROfusion Enabling Research scheme to demonstrate direct control of the plasma detachment. The project is granted 1.5 M€ for carrying out the work on TCV tokamak with DIFFER group leader Matthijs van Berkel as principal investigator.
The safe operation of future ITER and DEMO fusion reactors requires active control to monitor, maintain, and suppress disturbances on the key plasma parameters, including the control of the exhaust of heat and particles from the core to the divertor target. The project entails to use the full capability of the 10 camera MANTIS system. This yields one of the best real-time spatial and temporal resolution measurements which can be translated to directly observe and control ionisation (excitation), recombination, molecular processes, and impurity radiation near the plasma edge.
The crux lies in the development and employment of new technology, where state-of-the-art multivariable control is coupled to direct feedback on the loss-processes that drive the detachment process (rather than controlling detachment proxies). Hence the project involves a dedicated multiple-input multiple-output (MIMO) control approach that is based on accurate and fast (physics) models, and active and simultaneous multiple gas injection (D2 and N2). The system will be demonstrated to yield direct control of plasma detachment in the TCV reactor.