The construction of the Divertor Tokamak Test Facility (DTT), a strategic infrastructure in the roadmap to the exploitation of nuclear fusion as source of energy (1), compatible with the respect environment needs, is moving ahead. The project involves the most advanced industries and the Italian national scientific community.

It is one of the largest and ambitious European science and technology project supported by national and private funding of 600 million euro and will involve some hundreds of highly qualified personnel, for more than 30 years, both directly and in the supply chain. DTT will be constructed in Italy in the ENEA Research Centre of Frascati and supported by EUROfusion, the European consortium for scientific fusion research activities.

DTT is developed in collaboration between ENEA, Consortium CREATE, ENI, INFN, Consortium RFX, Politecnico di Torino, University of Tuscia, University of Milano-Bicocca, Università di Roma Tor-Vergata and some of the most prestigious leading universities and national research institutions and it was established as a connecting link between the major international nuclear fusion projects ITER (2) and DEMO (the reactor expected to generate electricity from fusion energy by 2050). The challenge aim is to provide scientific and technological answers to crucial issues such as the management of great  power flows produced by plasma fuel and to perform the resulting studies about materials to be used as a “container” capable of withstanding this very high temperatures.

DTT is expected to have a significant impact on the whole scientific community and also on Italian and European companies too. as of today's date, fusion research has brought quite considerable results in scientific and economic terms, with important positive repercussions on Italian companies. ITER, for instance, involves over 500 italian companies, including Ansaldo nucleare, ASG Superconductors, (Malacalza Group), SIMIC, Mangiarotti, Walter Tosto, Delta TI, OCEM Energy Technology, Angelantoni Test Technologies, Zanon, CECOM and the ICAS Consortium among ENEA, Criotec and Tratos, which have been assigned tenders corresponding to almost a billion euro, about 60% of the value of the European orders for high-tech components and the goal is generating new contracts for other hundreds of million euro in the next five years.

The underlying technology of DTT will be the same used for ITER with the additional advantage of being able to accept and carry a large package of testing opportunities. The D-shaped DTT will be a hyper-technological cylinder, ten meter high with a 5 meter radius, inside which about 30 m³ of plasma are brought to a temperature of over 100 million degrees with a current intensity of about 6 million amperes (equal to the current of six million lamps) and a thermal load on materials up to a dozen million watts per square meter (over double the power of a rocket taking off).

The “heated” plasma will work at a temperature of over 100 million degrees, while the 26 km of niobium-tin and the 16 niobium-titanium superconductors cables just a few centimetres away, will be at a temperature of 269° below zero.

The target of the power source is the divertor, key element of the tokamak, subject to element thermal stress analysis Tungsten (W), which is considered a plasma-facing material for the divertor or liquid metals for innovative and advanced technology designs. The divertor can be removable and replaced thanks to advanced remote handling systems.

Thanks to last generation superconducting materials developed at ENEA in collaboration with industries of this sector, the plasma inside the DTT will reach an energy density similar to that of the future reactor and, in this framework, the objective of the scientific community will be to guarantee the optimal efficiency of the good confinement associated with each scenario of the test configuration package.

Italy is leader in fusion research, our Country is among the main partners of the European Agiencies EUROfusion and Fusion for Energy (F4E) Organisation and is part of the major international research programmes: DEMO, Broader Approach and ITER.

NOTES:

1) Nuclear fusion is the exact opposite of nuclear fission, and it has the objective of producing safe, clean, inexhaustible and cheap energy capable of replacing fossil fuels, simulating the physics process that powers the stars.

2) ITER is a global project worth 20 billion euro, run by seven member countries (China, Japan, India, South Korea, Russia, USA and EU, conceived to demonstrate the feasibility of fusion energy in Cadarache, France. ITER is an experimental reactor which is 30 meters tall and weights 23.000 tonnes, expected to achieve power generation. It’s one of the biggest and most complex engineering project at global level, based strongly on collaborations and synergies between research and industry in technologically advanced areas.

• Nov 2017: Fusion Engineering and Design publishes a special issue on DTT (Special Section of FED Vol 122, 2017, pp 253-294 and E1-E25
• April 2019 ENEA publishes “DTT - Divertor Tokamak Test facility – Interim Design Report” (“Green Book”) (https://www.dtt-project.enea.it/downloads/DTT_IDR_2019_WEB.pdf)