Fusion Energy: What Are The Critical Supply Chain Pieces?
And how do they impact the road to commercial fusion?
One of the roads to the launch of commercial fusion energy goes right through the health of the fusion energy supply chain, and the companies that provide products and services into the fusion ecosystem. The Fusion Report has been monitoring this area for some time; here is our update on the fusion energy supply chain for mid-2025.
Of course, the first relevant question is “what are the critical components provided by the fusion energy supply chain”? While this depends significantly on the type of approach to fusion energy (magnetic confinement fusion (MCF); inertial confinement fusion (MCF); or hybrid fusion), there are several components that are more or less common, as well as ones that are highly critical for a specific type of fusion. We will focus this article on three specific supply chain “links”: thermal blankets, Marx generators, and high-temperature superconductor (HTS) components.
Thermal Blankets
In a fusion machine, a thermal blanket has two functions: i) converting high-energy neutrons into heat; and ii) breeding tritium (if you need more info on this concept, please see our November 2024 article here). With few exceptions (Helion’s fusion concept being one of them), thermal blankets are ubiquitous to fusion machines, regardless of the approach to fusion. The key components of the thermal blanket include the first wall, the main shield block, the breeder material, the coolant channels, thermal blanket structural support, and the tritium extraction system.
From a supply chain acquisition perspective, thermal blankets are problematic. The design of a thermal blanket is very specific to the design of the fusion machine itself. As an illustration, most tokamaks and stellarators require solid first walls and shield blocks, while some inertial fusion machines utilize “liquid” thermal blankets that do not have a first wall or shield block. Moreover, even in tokamaks and stellarators the position, size, and geometry are intimately tied to the size and geometry of the machine, making “supplier involvement” difficult to say the least. At best, the first walls, tritium extraction system, and the thermal blanket “medium” (the material that absorbs neutrons and extract the heat) could be procured from a vendor. To date, the only “privately acquirable” components in a thermal blanket are the tritium separators; publicly named companies building these include Tyne Engineering, Torion Plasma, Astral Systems, Kronos Fusion, and Kyoto Fusioneering.
Marx Generators
While generally associated with inertial confinement fusion (ICF), Marx Generators (see our “Basics” article here) are also used in Z-pinch machines, which are generally considered magnetic confinement fusion (MCF) systems. In simple terms, a Marx Generator puts out high-voltage pulses that can be used to drive a number of components in a fusion machine. The critical components in a Marx Generator are its capacitors and its spark gaps.
There are several companies that manufacture Marx Generators; they include: APELC, HVP High Voltage Products GmbH, Matsusada Precision, PPM Power, and Physical Optics Corporation. Note that not all of these companies build Marx Generators specifically for fusion machines; in many cases they are used for applications such as flash X-ray generation, high-power repetitive Marx (HPRM; most like the fusion machine use case), high-power microwave (HPM) generation, and material studies.
The capacitors in a Marx Generator store the energy until it is released; generally, these capacitors are high-power, high-voltage thin film capacitors. Manufacturers of these devices, which are used in a number of pulsed-power systems, include: Electrocube, Murata, Exxelia, Vishay, Electronic Concepts Inc., Rubycon, Knowles Precision Devices, Nichicon, Electrocon, and Nippon Chemi-con. The typical problem for fusion machines revolves around getting capacitors that will provide a long lifetime (>3 years, or close to 100 million “firings) and can operate under high temperatures. For spark gaps (which unsurprisingly have similar requirements to the capacitors), manufacturers include Teledyne e2v, High Energy Devices, Excelitas, Ross Engineering Corporation, Citel, Phoenix Contact, and TDK.
High-Temperature Superconductor (HTS) Components
Of the three critical technologies, the one besides Marx Generators (and their associated components) which have a “healthy” supply chain are HTS components. Companies that manufacture these components include: Farady Factory Japan LLC, Fujikura Ltd., SuperPower Incorporated/Furukawa Electric, American Superconductor Corporation, Bruker Energy and Supercon Technologies, High Temperature Superconductors, Japan Superconductor Technology, Sumitomo Electric Industries, and SuperMag Technology. Smaller companies working in this space include Nexans, Theva, HyperTech Research, MetOX, STI, SuNam, and Samri. Interestingly, most of the manufacturers of HTS components, whether HTS cables or HTS tapes, are in Japan.
Summary: Other Contenders for Critical Supply Chain Components
While these technologies, and the companies in those ecosystems, are some of the most visible critical supply chain technologies for fusion machines, they are not the only ones. Other critical technologies revolve around the creation of fusion machine fuels, fuel injection systems, fusion waste product removal, cryogenic vacuum systems, and software for the management, monitoring, and diagnosis of issues within fusion systems. The Fusion Report will have ongoing coverage of these areas as part of the next several articles that we publish.
Join us August 12 for Fusion 2035: The 10-Year Shot Clock, a half-day webinar featuring leaders from across the fusion ecosystem.
