What is SupraFusion?
SupraFusion is a research program funded by the French government as part of the France 2030 plan.
SupraFusion aims to develop a French technology cluster in the field of high-temperature superconductor (HTSc) applications, using magnetic confinement fusion as a driving force for research and innovation.
The recent and rapid development of high-temperature superconductors (HTSc) represents a potentially major breakthrough for the societal applications of superconductivity. Thanks to their performance, HTSc could create a paradigm shift, enabling in particular the design of compact magnetic fusion reactors. This could accelerate the advent of fusion power generation. HTS could also lead to major breakthroughs in other fields such as wind energy, medical imaging, low-carbon mobility, high-energy physics and high-field materials science.
In the longer term, when SHT technologies are in widespread use, the expertise acquired during this program will put French laboratories and industries in a strong position to face up to the global competition in this field. Several international initiatives, both public and private, are currently attempting to accelerate the development and deployment of this technology.
What is a high-temperature superconductor (HTS)?
Superconductors are materials capable of conducting electricity without any resistance when cooled below a certain temperature, known as the critical temperature. Unlike conventional superconductors, which require cooling close to absolute zero (around -269°C or 4 K), HTS become superconductors at higher temperatures (90 K for the most widely used material, REBCO).
Why are they revolutionary?
- They are superconducting in liquid nitrogen, an industrial fluid, for applications that do not require a high magnetic field (e.g. electrical cables).
- They generate magnetic fields far superior to those of conventional superconductors, a major advance for nuclear fusion and NMR spectrometers, among others.
What is magnetic fusion?
Stars produce their energy by fusing hydrogen nuclei. Toharness fusion on Earth, we use a mixture of two hydrogen isotopes, deuterium and tritium, as this is the most efficient reaction.
As the nuclei are positively charged and repel each other, temperatures of around 150 million degrees must be reached. Under these conditions, the mixture of deuterium and tritium is a plasma, made up of nuclei and free electrons.
These charged particles are sensitive to the magnetic field, which constrains their movement in directions perpendicular to the field. This makes it possible to use powerful electromagnets to confine the plasma, acting as an insulator between the fusion plasma and the machine wall.
A fusion reaction produces a helium nucleus, whose energy heats the plasma, and a neutron that directly heats the wall. The wall is cooled by circulating water, enabling the heat to be used directly or to power turbines to generate electricity.
Why is fusion an interesting source of energy?
- Fusion will be an energy source that does not directly emit greenhouse gases, that can be controlled, with no risk of runaway, and whose only waste is the machine itself.
- Thanks to its high energy density, fusion is economical with natural resources.
The mission of the research program
A major national project
SupraFusion is a large-scale national research project supported by CEA, CNRS, numerous universities and industrial partners.
Major advances
The aim of the program is to enable major advances in magnetic confinement fusion, with optimized superconducting technologies.
Research applications
The research resulting from this program will have a wide range of applications, from medical imaging to low-carbon mobility and energy production and storage.
French research around the world
In the longer term, when HTS technologies are in widespread use, the expertise acquired during this program will put French laboratories and our industry in a strong position to face up to the global competition that lies ahead in this field.
Challenges met by the program
The SupraFusion program aims to follow a progressive path towards the development and maturity of HTS technologies for future societal applications.
This implies meeting 5 major challenges:
Challenge no. 1: A well-known, high-quality HCA
The "basic raw material" is the first step in any technological application. HTS materials are available to industry today in ribbon form, but with a high degree of variability in performance between manufacturers and within the same production batch. In addition, due to the needs of early HTS applications, some of the magnetic performances of these materials have been extensively studied, but not all their usage properties (mechanical, thermal, etc.), which should also be well known for the design of large-scale applications. The ribbon must be adapted to the intended application.
Challenge 2: develop a high-performance driver
Unlike the small coils developed to date, large-scale applications can't simply use a ribbon as a conductor. Indeed, large magnets store a great deal of magnetic energy and are subject to significant Lorentz forces that cannot be withstood by a HTS ribbon alone, requiring the use of conductors reinforced with a large number of ribbons. There is considerable scope for innovation in these conductors.
Challenge 3: Managing safe winding operation
Magnet protection during accidental loss of the superconducting state (transition to the resistive state) is a major challenge that has long slowed the development and use of HTS technologies. Due to the high current densities carried in the HTS, the loss of the superconducting state heats up the conductor very quickly by Joule effect and severely damages the magnet if it is not effectively protected. Due to their specific properties, it is much more difficult to detect the transition of a HTS magnet and protect it properly than for a conventional superconducting magnet. Solutions have been found in some cases for low-energy (sub-MJ) HTS magnets. No clearly identified solutions exist for high-energy magnets (over 100 MJ).
Challenge 4: Create a large SHTC magnet
The realization of magnets with a high field strength (≥ 20T on the conductor) in a large aperture (1-2 m), leading to high magnetic energy (~ 100 MJ) is a major challenge, but one that is unavoidable for the development of several societal applications, in particular for magnetic fusion. We need to demonstrate the ability to work at high currents (> 40 kA), withstand enormous Lorentz forces, protect a 100 MJ SHTC magnet, demonstrate the successful integration of all the technological building blocks, and manufacture magnets in industry rather than in laboratories.
Challenge 5: Rethink applications and needs
HTS magnets are a disruptive technology with the potential to completely change the place of superconducting technologies in tomorrow's society. To achieve this, we need to build two-way bridges between HTS technology and end-users. This is particularly the case for fusion power plants, where the use of high-field magnets has a major impact on the design. The same applies to other applications, which need to be rethought in light of the possibilities offered by HTS.
Challenge 6: Coordinate interdisciplinary research, provide training and disseminate HCAI technologies.
The spectrum of skills, communities and industries needed to master HTS technology and ensure French leadership in the sector is very broad. Federating and training all the players around ambitious technological objectives is a challenge. Meeting this challenge will enable HTS technologies to be disseminated throughout society.
In order to meet each of the major challenges identified along the way, the 7-year program is built around 5 targeted research projects, 2 calls for projects, and cross-functional actions to promote, train and disseminate results.
Detailed work plan
These actions focus on three areas
The SupraFusion program is part of France’s drive to make high-temperature superconductors (HTCs) a strategic asset in the fields of energy, technology and industry.
Its three-pronged roadmap aims to consolidate national expertise and strengthen France’s position in this fast-changing sector.
- The first axis focuses on the development of essential technological building blocks, ensuring high-performance materials and components.
- The second axis is devoted to large-scale demonstration, validating the feasibility of HTCs for industrial applications, notably in nuclear fusion.
- Finally, the third axis explores new applications, from compact fusion reactors to advances in medical imaging, power grids and low-carbon mobility.
By bringing together laboratories, institutions and industry, SupraFusion aims to position France at the forefront of this technology and contribute to its scientific and economic influence.
2nd Axis
The aim of the second axis is to build and test a large-scale magnet in order to demonstrate the feasibility of scaling up the technology to a technological maturity level (TRL) of 4.
Large-scale demonstrator
3rd Axis
Finally, the last axis aims to prepare for these breakthroughs in society, both on the specific theme of compact fusion machines and on broad societal applications.
Compact all-SHT magnetic fusion reactors