The design phase of DTT is towards its finalization and construction has started on the Frascati side. The DTT design has required an intense activity of scenario modelling to provide target plasmas for diagnostics, magnetic controls, neutron shielding, heating mix definition and many other aspects. This PhD work will be part of this modelling framework for DTT. A specific focus will be on impurity seeded plasma in detached divertor conditions, and will include analysis and modelling of present devices, in particular JET. Scenarios with negative triangularity may also be included. The modelling will concern the core plasma up to the separatrix, and will be connected to scrape-off layer modelling done by other DTT groups. Codes used will be ASTRA and JINTRAC/HFPS, with use of IMAS for storing results. Periods of activity abroad with a minimum of 2 months in total over the 3 years are requested by the PhD course, which will be based at the University of Milano Bicocca (very close to ISTP/CNR). Courses and exams are foreseen in parallel with the research activity. The application deadline will probably be in July with interviews in September (still to be finalised) but expression of interest is encouraged as soon as possible by writing to paola.mantica@istp.cnr.it.