For fusion energy systems to run safely and consistently, researchers must closely track the behaviour of superheated plasma fuel.
Key characteristics such as temperature and density directly influence whether fusion reactions can be sustained.
Measuring these extreme conditions requires advanced instruments known as diagnostics, which act as the eyes and ears inside a fusion device.
A new report, backed by the US Department of Energy (DOE), calls for stronger investment in the nation's fusion diagnostic capabilities.
The document argues that improving these tools is essential for giving DOE and Congress the data needed to accelerate the development of commercial fusion power plants.
DOE workshop on measurement innovation
The report stems from the DOE's 2024 Basic Research Needs Workshop on Measurement Innovation, organised through the Office of Science's Fusion Energy Sciences (FES) programme.
Luis Delgado-Aparicio, head of advanced projects at the DOE's Princeton Plasma Physics Laboratory (PPPL), chaired the effort, with Sean Regan, director of the Experimental Division at the University of Rochester's Laboratory for Laser Energetics, serving as co-chair.
Participants included specialists from universities, private companies, and national laboratories such as PPPL.
Their goal was to determine which diagnostic and measurement technologies are most urgently needed to maintain US leadership in fusion energy and plasma science.
The workshop also supported the objectives of the DOE's Fusion Science & Technology Roadmap, which "targets actions and milestones out to the mid-2030s, providing the scientific and technological foundation to support a competitive US fusion energy industry."
"Measurement innovations have led and will continue to lead to scientific and engineering breakthroughs in plasma science and technology activities supported by the DOE's FES, especially fusion energy sciences," said Delgado-Aparicio.
"This new report provides substantive findings across seven key areas of plasma and fusion science and technology.
“We believe it will impact both the public and private fusion communities in a meaningful way."
"The findings in this report are a testament to the critical role of diagnostics in driving fusion energy science forward," said Regan.
"By investing in innovative measurement technologies, we can accelerate progress toward commercial fusion energy and strengthen America's leadership in plasma science."
Tougher sensors, faster measurements and AI tools
The experts identified several ways the federal government could strengthen the nation's ability to measure plasma effectively.
One priority is developing diagnostics that can endure the intense radiation levels expected inside future fusion power plants.
Another is creating new techniques capable of capturing the extremely fast events that occur during ICF experiments.
The report also highlights the use of artificial intelligence (AI) to streamline the design of advanced measurement systems.
In addition, it calls for building a strong workforce pipeline to attract and train the next generation of diagnostic scientists.
These capabilities not only support fusion energy but also reinforce a broader plasma technology ecosystem that contributes to US economic competitiveness.
"Both Luis and I thank the members of the working groups and the broader community for their dedication and hard work in putting this report together," Regan said.
"Their expertise and collaboration have been instrumental in identifying the critical innovations needed to advance diagnostic technologies."
Major recommendations to accelerate fusion innovation
The report outlines several key recommendations:
• Accelerate innovation: Speed progress in measurement technologies by validating and verifying modelling codes, AI and machine learning tools, and digital twins
• Establish a national network: Create a coordinated measurement innovation community modelled after LaserNetUS, potentially called CalibrationNetUS
• Form national teams: Assemble national groups to efficiently transform new measurement concepts into working diagnostic tools
• Standardise calibrations: Adopt a more systematic approach to calibrating diagnostic instruments
• Transfer knowledge to the private sector: Share diagnostic expertise and operational experience from public institutions with private fusion companies
• Invest in a workforce pipeline: Expand workforce development efforts to meet the needs of fusion pilot plants
• Plan now for remote operations: Address the diagnostic tools required for remote operation and maintenance of future fusion facilities in upcoming workshops