Ludovica De Gianni ^1* Guido Ciraolo ¹ Gerardo Giruzzi ¹ Gloria Falchetto ¹ Nicolas Rivals ¹ krzysztof Gałazka ^1,2 Luca Balbinot ³ Naren Varadarajan ¹ Srikanth Sureshkumar ¹ Jean-Francois Artaud ¹ Hugo Bufferand ¹ Raffael Düll ¹ Alberto Gallo ¹ Philippe Ghendrih ¹ Virginia Quadri ¹ Giulio Rubino ⁴ Patrick Tamain ¹

• ¹ Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Paris, France
• ² Institute of Plasma Physics and Laser Microfusion, Warsaw, Masovian, Poland
• ³ University of Tuscia, Viterbo, Lazio, Italy
• ⁴ Institute for Plasma Science and Technology, Department of Physical Sciences and Technologies of Matter, National Research Council (CNR), Bari, Italy

In its first phase of exploitation, JT-60SA will be equipped with an inertially cooled divertor, which can sustain heat loads of 10 MW/m2 on the targets for a few seconds, that is much shorter than the intended discharge duration.Therefore, in order to maximize the duration of discharges, it is crucial to develop operational scenarios with a high radiated fraction in the plasma edge region, without unacceptably compromising the scenario performance.In this study, core and edge conditions of unseeded and neon seeded deuterium H-mode scenarios in JT-60SA have been investigated with METIS and SOLEDGE3X-EIRENE.The aim was to determine whether, and under which operational conditions, it would be possible to achieve heat loads at the targets significantly lower than 10 MW/m2, and potentially establish a divertor detached regime, while keeping favorable plasma core conditions. In first analysis, an investigation of the edge parameter space of unseeded scenarios has been carried out.Simulations at intermediate edge power of 15 MW indicate that, without seeded impurities, the heat loads at the targets are higher than 10 MW/m2 in attached cases, and achieving detachment is challenging, requiring upstream electron densities at least above 4 • 10 19 m-3. This points towards the need for impurities injection during the first period of exploitation of the machine. Therefore, neon seeding simulations have been carried out, performing a seeding rate scan and an injected power scan, while keeping the upstream electron density at the separatrix at 3 • 10 19 m-3. We show that at 15 MW of power injected in the edge plasma, the inner target is easily detached when injecting neon, with low heat loads. However, at the outer target the heat fluxes are not lowered below 10 MW/m2, even when the power losses in the edge plasma are equal to the 50% of the power crossing the separatrix. Therefore, the tokamak will probably need to be operated in deep detached regime in its first phase of exploitation for discharges longer than a few seconds.In the framework of core-edge integrated modeling, using METIS, the power radiated in the core has been computed for the most interesting cases.