The heating systems capability of DTT

The purpose of the italian Divertor Tokamak Test (DTT, 6 T, 5.5 MA, R0 = 2.08 m, a = 0.65 m for ~ 100 s) is to study power exhaust and divertor load in an integrated plasma scenario. To accomplish this mission DTT will be equipped with 45 MW of additional heating power to fulfill a PSEP/R >= 15 MW/m studing alternative divertor configurations in view of ITER operations and DEMO design. The heating systems considered are NNBI (Negative Neutral Beam Injector), ECH (Electron Cyclotron Heating) and ICH (Ion Cyclotron Heating). Power repartition is based on the physical and functional requirements resulting from the review of the initial design [1]. The ECH is based on the use of 170GHz/1MW gyrotron, exploiting the development done for ITER and the experience of W7-X EC system. To fulfill major requirements assigned to EC waves 20-30 MW at plasma are foreseen. The NNBI system will be based on two beamlines providing deuterium negative ions (D-) at 300 keV and an injected power of 5-8 MW each. To increase efficiency and controllability, a modular approach will be adopted for the ion source and accelerator. The main task of the ICH system is the central deposition in different heating schemes (mode conversion, minority heating and the novel three ions scheme). The frequency range is 60-90 MHz with a coupled power of 5-10 MW depending on the adopted antenna. A high reliability in delivering power to plasma will be obtained considering consolidated and available technologies together with a design architecture capable to reduce the fault risks. An overview of the three systems will be given, with a particular attention to the design integration in the DTT plant and to synergetic aspects between them.