THE PROJECT DTT 

 

The EUROfusion consortium, which deals with research on controlled thermonuclear fusion on behalf of the European Union, has defined a road map aimed at leading us, by 2050, to the realization of fusion energy with a demonstration plant called DEMO.

One of the main challenges of the roadmap is the development of a divertor system, capable of absorbing the significant thermal loads associated with the phenomenon of plasma exhaust. The ITER reactor, an international Tokamak under construction in France, involves the design and testing of a conventional divertor. In parallel, EUROfusion has promoted the study of alternative solutions to be used in DEMO. The project of the new tokamak called "Divertor Tokamak Test facility" (DTT) fits into this framework has been proposed with the ambitious aim of studying and experimenting with possible alternative solutions, including advanced magnetic configurations and liquid metal amusement. Therefore, DTT fits perfectly with the EUROfusion proposal to look for alternative divertor solution.

The proposal was made by over one hundred researchers from ENEA, CNR and from various Italian universities, with the support of some international laboratories and the contribution of scientists from several European institutions. The results are collected in the publication  “DTT-Divertor Tokamak Test facility. Project Proposal", ISBN 978-88-8286-318-0, pubblicato nel 2015 (DTT" Blue Book ") and in several scientific papers, including the Special Issue in Fusion Engineering and Design, November 2017 (Special Section: DTT , Fusion Engineering and Design, Vol. 122, 2017).

After the publication of the Blue Book, the DTT project team continued its intense activity with the dual objective of articulating an organizational and financial proposal (site selection, organizational structure, cost review, etc.) and, furthermore, to deepen some critical design issues (introduction of vertical symmetry configurations, verification of parameters, revision of subsystems, etc.).

The new version of the project is described in a new report, entitled  “DTT Divertor Tokamak Test facility Interim Design Report, ENEA (ISBN 978-88-8286-378-4), April 2019 ("Green Book")".

DTT will operate in power conditions at the plasma border very similar to those foreseen for DEMO. The optimization of the project led to the choice of a plasma majour radius R = 2.10 m, with an aspect ratio equal A = 3.23 (A = R/a, where 'a' is the plasma minor radius), a toroidal field BT = 6 T, a plasma current Ip = 5.5 MA, and an additional power PTot = 45 MW.

DTT will be a facility capable of experimenting with different divertor topologies, in the typical regimes of the DEMO. Different materials (tungsten, liquid metals) will be tested up to a power density in the order of 20 MW/m2. Beyond the strict application to the fusion technology, the DTT will provide a precious opportunity for the development of innovative technologies relevant for different applications and the creation of possible industrial spin-off opportunities for all European countries.

The timetable of the DTT foresees the first plasma in 2025 and, subsequently, a period of operations of over 20 years, up to the initial phases of the realization of the DEMO.

The project will have a strong positive employment impact, estimated at 1000 man years for construction and around 3000 man years for carrying out the operations, with an economic drag coefficient of the induced activities estimated in the order of 2-2.5.

The cost of the project is estimated at around € 500 million covered for the most part by the Italian government, with a contribution of € 60 million of EUROfusion. An important contribution (€ 25 million) is also provided by the Regione Lazio.

 

Further information on DTT can be found on the official project website