The IFuEL project is developing efficient solid-state laser technology for sustainable fusion energy and provides testing facilities for plasma-facing materials.
The IFuEL project is at the forefront of advances in solid-state laser technology. As global demand for clean energy increases, this initiative addresses the challenges associated with inertial fusion power generation, while striving to reduce costs and improve efficiency. By developing innovative laser systems, the IFuEL project aims to increase the feasibility of fusion energy and pave the way to a cleaner and more sustainable future. IFuEL project coordinator Franz X. Keltner discusses the project’s main priorities, current status, challenges faced and potential impact on the future of fusion energy.
What are your current project priorities?
The main goal of this project is to demonstrate a highly efficient and cost-effective solid-state laser technology that can later be scaled up for internal fusion energy needs. The current goal is to demonstrate that two laser heads, each producing 100 J nanosecond pulses at closely spaced wavelengths, can be combined incoherently to produce a 200 J output pulse and operate at a pulse repetition rate of 10 Hz. The output also doubles the frequency and becomes green. The pulses are used to study plasma-wall interactions in interaction chambers by colliding high-power and high-energy laser beams to generate high-energy particles and plasma streams within cryogenic hydrogen/helium jets. These long-term experiments also demonstrate the operational stability of the laser system.
What stage is the project currently at and what is the action plan for the next year?
The project will begin on January 1, 2026 and is currently recruiting 15 staff spread across the four participating centres. We are also working on preliminary designs for the laser amplifier and vacuum chamber that will need to be constructed. The total duration of the project is only 3 years, and some items have a delivery time of 9 to 12 months, so long-lead items must be ordered.
What key challenges does the project seek to overcome?
The main challenges of this project are to design, build, and validate a cryogenically cooled laser head to be able to generate 100 J-level laser pulses at a 10 Hz repetition rate with high (i.e., 25%) wall-plug efficiency and to reduce optical pump power due to the long upper state lifetime when compared to competing approaches. This means that the pump diode power and peak current required to drive the laser system is approximately five times lower than alternative technologies. Yb:YLF is used as the gain medium due to its low quantum defects of only 3-6% and good thermo-optic properties.
How important is international cooperation to the project?
Although we do not rely heavily on international collaboration for current developments, we also have strong ties to the Laser Energy Laboratory in Rochester, New York, and the National Ignition Facility at Lawrence Livermore National Laboratory. We hope that due to our common interests, these relationships will develop into strong cooperation over the course of this project.
What impact is iFuEL expected to have on the future of fusion?
IFuEL promises to deliver a laser with wall plug efficiency approximately twice as high as alternative laser technologies previously considered for fusion laser technology. Furthermore, the gain medium has a five times longer accumulation time. This means that only one fifth of the pump current is required. Both factors reduce the optical pump power required to achieve the same output laser power by an order of magnitude. Since pump diodes are one of the major costs of fusion lasers, our laser technology should be an order of magnitude cheaper, bringing fusion energy much closer to becoming a viable energy source. In addition, the required fusion gain could be reduced by a factor of two before energy-producing inertial fusion power plants could be built. This could significantly reduce the time it takes for inertial fusion energy to be available for energy production. Testing new lasers to generate plasma and streams of charged particles will allow researchers to expose and study the durability of reactor wall materials under fusion-related conditions. Such testing facilities are critically needed to study new materials that are more resistant to hydrogen uptake, such as high-entropy solids.
This project is funded by the Federal Ministry of Education and Research (BMFTR) as part of the Fusion 2040 program.
Please note: This is a commercial profile
This article will also be published in the quarterly magazine issue 26.
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