Initial design of a real-time and an intershot bolometric data exploitation strategy for DTT

Abstract One of the milestones to be achieved in the design of the bolometric diagnostics for the new Italian Divertor Tokamak Test (DTT) project is the estimation of the radiated power at the start of operation, i.e. the so-called first plasma, in order to perform various tasks ranging from scientific analysis and planning of the discharges to the feedback protection of the machine. In fact, real-time (RT) feedback control of the radiation pattern for prevention is both a delicate and important matter, for example in terms of mitigating and avoiding disruptions. It would therefore be desirable to monitor not only the total power emitted, but also the one emitted by the different regions of the plasma. This paper then focuses on showing the initial design of the main strategy for estimating the plasma radiation in two different situations: for RT control and for an inter-shot analysis. The first approach for RT then, is based on the estimation of the radiated power inside the first wall using specific lines of sight (LoS). Such estimates have been compared with those obtained from slower tomographic reconstructions of synthetic emissivity profiles ( phantoms ). Furthermore, a first design of the Region Of Interest (ROI) for a fast implementation of an already established macro-estimation of the radiated power in different locations of the main chamber is provided and the overall method is adapted for DTT. Regarding the design of the inter-shot data exploitation then, since tomographic reconstructions will most likely be available during an inter-shot basis, it is planned to provide a more accurate estimate of the radiated power from different locations of the device for a better design and tuning of the discharges. In order to achieve such a long-term goal, an initial strategy for adapting a maximum likelihood based algorithm for inter-shot analysis is described.