ITER: The most ambitious energy research project of our times


The world has an energy issue: with demand likely to triple before the end of the century, the race is on for a sustainable and abundant energy supply.

Energy generated from nuclear fusion could be one answer and ITER - one of the most ambitious energy research projects ever seen – is at the forefront of fusion research.


35 nations have joined forces in the ITER project, by far the largest international experimental campaign that is crucial to advancing nuclear fusion science and preparing the way for the nuclear fusion power plants of tomorrow.


Nuclear fusion is a natural process that takes place in stars such as the Sun, where incredibly strong gravity and high temperatures cause lightweight nuclei (a nucleus is part of an atom) to collide and join together into heavier atoms, releasing an enormous amount of energy at the same time. This energy is intrinsically safe, non-carbon emitting and virtually limitless.


Engineers and scientists from all over the world are constructing a research nuclear fusion reactor based on the tokamak principle, a doughnut-shaped vessel designed to harness fusion energy. ITER, which means the “way” in Latin, aims to prove that it is possible to produce a net energy gain from nuclear fusion. It aims to solve the technological and scientific challenges that currently prevent us from being able to design a future fusion electricity production. A large facility to host the tokamak is currently being built in Cadarache in the South of France, after assembly operations started in July 2020.

ITER is one of the most ambitious scientific research projects of our times, representing a key experimental step towards the next phase of energy production.



The ITER machine will weigh more than three times the weight of the Eiffel Tower’s metal frame.


km long

The superconducting strands necessary for the tokamak field magnets would wrap around the Earth’s equator twice.


degrees Celsius

Gas atoms inside ITER’s tokamak take the form of plasma, with temperatures ten times the temperature in the core of the Sun.


In comparison to the fission process (in which atoms are split), fusion has two main advantages:

It does not produce extremely long-lasting waste products that need to be stored for thousands of years; fusion activated materials can be re-used again after 100 years.

Nuclear fusion reactors are not subject to the risk of uncontrolled chain reactions, which can cause extremely dangerous accidents and the eventual explosion of the reactor itself.


The price to pay for cleaner energy is the difficulty we face in achieving nuclear fusion, mostly due to the extremely high temperatures involved in the process, as well as plasma’s densities and confinement timings.

Additionally, the interior tokamak machine components cannot be handled manually due to the need to maintain vacuum, the extremely constrained spaces, and radioactive materials. Maintenance is instead carried out by robots and through the help of automatic procedures. Therefore, not only designing, but also building and operating a complex machine like ITER, requires micrometric precision in the assembly process and machine operation.

Overall, the social impact outweighs the hurdles!

If we could use nuclear fusion energy production plant technology, we would be capable of rapidly generating large amounts of energy in an unprecedented way, using widely available raw fuel materials as common as water. We could completely end our dependency on fossil fuels and eradicate carbon-based energy provisioning. Our planet would benefit tremendously from the discovery of such a clean and affordable energy source.

For example, the potential nuclear fusion energy that ITER could extract from 100 litres of water and 100 grams of lithium (which is an element widely present in ocean water and on the Earth’s crust) is equivalent to the energy derived from burning 50 tons of oil, which would release 150 tons of polluting CO2 into the atmosphere.

ITER will not deliver electricity onto the grid for widespread use because it is a scientific research experiment. It will, however, pave the way to DEMO, Europe’s demonstration power plant that will generate net fusion electricity.

ITER therefore represents a fundamental milestone towards clean energy and sustainable power production.


Starting from 2036, ITER is expected to produce data related to its instruments and measurement tools (diagnostics), power, magnetic fields, and the outcomes of its experiments, at a rate of around 2 petabytes per day.

The facility will have to be able to store data locally as well as provide a copy of it to the European fusion agencies and ITER stakeholders worldwide.

This is where GÉANT comes into play. The ambitious energy research project is connected to the pan-European network through the French National Research and Education Network, RENATER. From 2013 to 2017, GÉANT supplied a 10Gbps link between Geneva and Washington, matched by the 10Gbps link between Japan and Washington provided by the Japanese NREN, SINET. The links enabled privileged access to the Japanese fusion research Supercomputer Helios to the scientists working on the ITER project.
More recently, GÉANT has given scientists the possibility to plan and conduct data transfer tests in the Remote Experimentation Centre in Rokkasho, Japan, providing a dedicated, stable and secure virtual private network (L2 VPN), in collaboration with RENATER and SINET, over the new direct interconnection between Japan and GÉANT, using a terrestrial fibre route across Europe and Asia.

Now working with ITER to provide data back-up links to their remote data centre in Denmark, GÉANT will also plan for their future requirements for worldwide data distribution.

The fusion community at EUROfusion – the ‘European Consortium for the Development of Fusion Energy’, which currently supports ITER, has been investigating its needs for authentication and authorisation for access to online research resources and services.

GÉANT is supporting this work and a technical proof of concept based on the AARC (Authentication and Authorisation for Research and Collaboration project) Blueprint Architecture has been successfully piloted. This will allow the EUROfusion users to effectively make use of Single Sign On (SSO) web while accessing their distributed services.

For more details about ITER and the project’s goals, visit



2 Exabytes* a year is already carried at high speed and low latency.

* (That’s 2 BILLION Gigabytes!)


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