How AI and International Collaboration Are Unlocking the Secrets of Plasma
Look up at the stars, witness a lightning bolt, or glance at a neon sign—you're encountering plasma, the fourth state of matter that constitutes an estimated 99.9% of the visible universe. Despite being the most abundant form of ordinary matter in the cosmos, plasma remains the least understood and most difficult to study.
From the fiery hearts of stars to the intricate dance of particles in experimental reactors, plasma physics represents one of science's final frontiers. Recent breakthroughs are dramatically accelerating our understanding: artificial intelligence is uncovering new physical laws, while unprecedented international collaborations are bringing the dream of fusion energy closer to reality. This article explores how cutting-edge research is unraveling plasma's mysteries and harnessing its potential to transform our energy future.
Artificial intelligence is revealing new physical laws in plasma physics that have eluded scientists for decades.
International projects are pooling resources and expertise to advance fusion energy research.
Plasma is often called the fourth state of matter, but what exactly does that mean? When a gas is heated or subjected to strong electromagnetic fields, its atoms begin to lose their electrons in a process called ionization. The result is plasma—a seething mixture of free-flowing ions and electrons that can conduct electricity and respond strongly to electromagnetic fields 2 .
Unlike the other states of matter, the transition to plasma isn't as clearly defined. As noted in plasma physics, "Whether a given degree of ionization suffices to call a substance 'plasma' depends on the specific phenomenon being considered" 2 . What makes plasma unique is its collective behavior—while gas particles interact mainly through brief collisions, plasma particles influence each other through long-range electric and magnetic fields, leading to complex waves and instabilities 2 .
Plasma is everywhere once you know where to look:
The systematic study of plasma began with Irving Langmuir and his colleagues in the 1920s. It was Langmuir who first coined the term "plasma," drawing an analogy to blood plasma because "the way blood plasma carries red and white corpuscles and germs" reminded him of how electrons are transported in ionized gas 2 .
In a groundbreaking study published in July 2025, physicists at Emory University demonstrated that artificial intelligence can discover fundamental physical laws that have eluded scientists for decades. Their research focused on dusty plasma—ionized gas containing suspended dust particles that commonly occurs in space environments like Saturn's rings and during wildfires on Earth 4 .
The research team, led by professors Justin Burton and Ilya Nemenman, designed an elegant experiment to study dusty plasma dynamics:
Tiny plastic particles were suspended in a vacuum chamber filled with plasma 4
A laser spread into a sheet of light moved up and down through the chamber while a high-speed camera captured images of the particles 4
Snapshots were assembled into stacks, revealing the three-dimensional location of individual particles over centimeter length scales for several minutes 4
| Equipment | Function |
|---|---|
| Vacuum chamber | Contains the plasma and suspended dust particles |
| Laser sheet illumination | Makes particle positions visible for tracking |
| High-speed camera | Captures particle movement over time |
| Tomographic imaging software | Reconstructs 3D particle trajectories from 2D images |
The real innovation came in how the team analyzed this data. Instead of using traditional physics models, they designed a specialized neural network that could infer the underlying laws governing particle interactions. "We needed to structure the network to follow the necessary rules while still allowing it to explore and infer unknown physics," Burton explained 4 .
The AI was constrained to model three independent contributions to particle motion:
This approach allowed the AI to discover with 99% accuracy the precise mathematics behind what physicists call non-reciprocal forces 4 .
Accuracy of AI in discovering non-reciprocal forces
The AI model revealed surprising details about how particles interact in dusty plasma. Nemenman explains these non-reciprocal forces using a nautical analogy: "The wake pattern of each boat affects the motion of the other boat. The wake of one boat may repel or attract the other boat depending on their relative positions" 4 .
"In dusty plasma, the team found that 'a leading particle attracts the trailing particle, but the trailing particle always repels the leading one.' This phenomenon had been theorized but never before described with such precision."
The AI also corrected two longstanding theoretical assumptions:
While understanding fundamental plasma physics is fascinating, one application drives much of the research: fusion energy. Fusion—the process that powers the Sun—offers the potential for nearly limitless clean energy if we can learn to sustain and control it on Earth.
The most developed approach to achieving fusion uses tokamaks—doughnut-shaped devices that confine plasma using powerful magnetic fields. The challenge is immense: plasma must be heated to temperatures of tens of millions of degrees while preventing it from touching and damaging the reactor walls 1 5 .
The international fusion community is pursuing this goal through several major projects:
The world's largest superconducting fusion system, built through collaboration between Japan and Europe
A massive multinational fusion facility under construction in France 1
A spherical tokamak at the University of Wisconsin-Madison studying non-inductive current drive 5
A German stellarator investigating alternative magnetic confinement configurations 5
As fusion devices become more advanced, so too must the tools to study them. The Princeton Plasma Physics Laboratory (PPPL) is providing a critical measurement tool called an X-ray imaging crystal spectrometer (XICS) for installation on JT-60SA in early 2026 1 .
This four-ton instrument measures X-rays emitted by plasma to determine temperature, speed, flow direction, and impurity density—all crucial parameters for maintaining stable fusion reactions. What makes PPPL's XICS special is its advanced calibration system that ensures accuracy regardless of changes in plasma density and temperature 1 .
"This calibration scheme has never been implemented before at this scale. Because JT-60SA will be such a powerful machine, we will access operating conditions that we have never achieved before. The measurements need to be very accurate for us to learn the science of those new regimes."
| Facility | Location | Type |
|---|---|---|
| JT-60SA | Japan | Tokamak |
| ITER | France | Tokamak |
| Wendelstein 7-X | Germany | Stellarator |
| Pegasus-III | USA | Spherical Tokamak |
| DIII-D | USA | Tokamak |
Modern plasma research relies on sophisticated equipment and technologies. Here are some key tools enabling breakthroughs in plasma physics:
Critical for confining hot plasma without excessive energy loss, these magnets must be cooled to extremely low temperatures to maintain superconductivity 1
Measures plasma temperature, flow speed, and impurity density by analyzing X-rays emitted by the plasma 1
Use laser sheets and high-speed cameras to track particle movements in 3D, as in the Emory dusty plasma experiments 4
Reconstructs 3D plasma properties from 2D measurements 4
Capture rapid plasma dynamics that would be invisible to the naked eye
Enable complex simulations of plasma behavior that would be impossible to calculate analytically 6
Stephen C. Jardin, a principal research physicist at Princeton Plasma Physics Laboratory, recently won the 2025 Ronald C. Davidson Award for Plasma Physics for his work using advanced computer modeling to explain the "sawtooth phenomena" in tokamaks—oscillations in plasma temperature that had puzzled scientists for decades 6 .
Jardin's work exemplifies how computational physics has become essential to plasma research. "For over four decades, the fastest computers have become about 1,000 times more powerful each decade," Jardin noted. "This has repeatedly opened new possibilities of performing new calculations that were impossible just a decade earlier" 6 .
Looking ahead, Jardin predicts that artificial intelligence will combine with advanced computing to open new research opportunities in the quest for practical fusion energy, similar to how it has revolutionized fields like aircraft design and weather prediction 6 .
The study of plasma has evolved dramatically from Langmuir's early observations to today's international collaborations and AI-driven discoveries. What makes this field so exciting is the convergence of fundamental research and practical applications—from understanding the behavior of cosmic plasma to harnessing fusion for clean energy.
"I think of it like the Star Trek motto, to boldly go where no one has before. Used properly, AI can open doors to whole new realms to explore."
The path forward will require continued global cooperation, as demonstrated by the partnership between the U.S., Japan, and Europe on JT-60SA. It will also demand innovative approaches that combine experimental facilities, advanced diagnostics, computational modeling, and artificial intelligence. As these tools converge, we're not just learning about the fourth state of matter—we're unlocking secrets that may one day power our world with starlight captured here on Earth.