Progress in the development of the ICRF system of DTT

This paper describes the design and realisation status of the Ion Cyclotron Range of Frequency (ICRF) system of the Divertor Tokamak Test facility (DTT). DTT requires a large amount of additional heating partially provided by an ICRF system working in the frequency range from 60 to 90 MHz. The system will be modular, with each module aimed at coupling at least 3 MW for 50 s every hour to the DTT reference plasma as well as to contribute to wall cleaning tasks with lower power and higher duty cycle. Compared to existing and planned ICRF plants for tokamaks and stellarators, the radiofrequency system of DTT presents some peculiar features, mostly with reference to the technology of radiofrequency generators and to the mix of challenges the antenna design has to face like geometry decomposition, remote assembly and maintenance. The system design started some years ago and, in the last two years, 50+ collaborators contributed to make advances in its definition and development. Recently the ICRF system of DTT entered its realisation phase, with the issue of the first calls for tender, one of which for the procurement of two radiofrequency sources, while some aspects are still under design. This contribution gives a brief overview of the system architecture and focuses on the major advancements achieved in the latest years.