Authored by Haley Zaremba via OilPrice.com,
A new Princeton Plasma Physics Laboratory model finds that heating plasma first and compressing it second could sharply cut the energy needed to reach fusion ignition.
Tungsten at just one part in 10,000 could double the pressure ignition requires, a red flag for the dozen-plus next-gen machines built with tungsten walls.
The findings are theoretical, but a liquid lithium coating could keep tungsten out of the plasma as AI-era money keeps pouring into fusion.
A new model for nuclear fusion has potentially discovered a significantly more energy-efficient way to achieve nuclear fusion, and flipped everything we thought we knew about the fusion process. The scientists' modelling also flips the traditional order of operations for managing and sustaining plasma in a controlled fusion experiment. Traditionally, fusion processes start by compressing plasma for higher density, and then heating it to superhot temperatures. However, new modelling from the United States Department of Energy's Princeton Plasma Physics Laboratory (PPPL) shows that reversing this order of operations could drastically reduce the energy inputs necessary to achieve ignition.
This is big. Ignition refers to when a fusion experiment creates more energy than it consumes. To date, this has been the biggest and most elusive challenge of achieving fusion - the process which powers our own sun - here on Earth. The first ever successful ignition was achieved in 2022 at California's Lawrence Livermore National Laboratory. And while this achievement has been repeated and other instances of ignition have occurred, the sector is still a far cry from creating enough net energy to be anywhere close to practical and commercial application.
Unlocking the secret to commercially scalable nuclear fusion would solve much of the world's energy problems essentially overnight. Fusion provides a near-limitless source of clean energy and yields none of the hazardous and radioactive spent nuclear fuel associated with nuclear fission. It's therefore viewed as a 'holy grail' of clean energy. This is why finding more energy-efficient pathways toward ignition is such a big deal, even if they are - at this point - purely theoretical.
But the team at PPPL didn't just discover how to make fusion easier. They also discovered a way to make fusion much, much more difficult - and found that it could be a major stumbling block for many of the nuclear fusion experiments and startups racing to achieve commercial nuclear fusion. The team found that the incorporation of just a tiny amount of the element tungsten in the fusion process - as small as one part of tungsten in 10,000 within the plasma - could cause the pressure needed to achieve ignition to double, creating major issues for efficiency and stability.
This is highly relevant for many next-gen fusion experiments which use tungsten in the design of their reactors. According to reporting from Interesting Engineering, "More than a dozen next-generation fusion machines have selected tungsten for their inner walls because the metal can withstand extremely high temperatures." If the tiniest bit of this tungsten enters the plasma, achieving fusion quickly becomes much more difficult, and could even make the experiment unstable.
Discovering this risk now may avoid a lot of wasted energy and expenditures going forward. And, happily, those tungsten-based reactors don't need to be scrapped; they just need to be coated, such as with liquid lithium, to ensure that the tungsten doesn't contaminate the plasma.
"While more study is needed, we are excited by these results, and they suggest a clear path forward for future research in this area," PPPL physicist Jonathan Menard told Interesting Engineering.
PPPL is far from alone in its enthusiasm for fusion research and its disruptive potential. After a century of slow and painstaking progress from very few players, the field of nuclear fusion is now exploding as investors take note of the accelerated developments in the field, and the AI boom causes VC money to flood into all kinds of alternative energies. As a result, startups are starting to crowd into the sector, creating more competition and leading to increased innovation.
Some of the tech sector's biggest names and deepest pockets are heavily involved in the burgeoning fusion sector. Microsoft's Bill Gates and OpenAI's Sam Altman are vocal advocates for and financial backers of nuclear fusion research as a critical solution to the energy monster their own companies are creating through the hyperscaling of AI data centers. Altman has admitted that the world simply doesn't have enough energy to support the tech sector's growth trajectory in a business-as-usual scenario.
"There's no way to get there without a breakthrough," he said at the 2024 World Economic Forum in Davos, Switzerland. "It motivates us to go invest more in fusion."