A powerful laser strikes a tiny target, and it instantly turns into a cloud of scorching gas — plasma. Within this cloud, magnetic fields spontaneously arise. Like invisible hands, they prevent heat from freely escaping the hot core. That's why such fields are important for nuclear fusion — the process that powers the Sun and that humans are trying to tame on Earth.

Physicists tracked these fields using proton beams. As protons fly through a magnetic field, their paths are slightly deflected — from these deviations, one can reconstruct the field's structure. They took snapshots twice: right after the laser shot and later. It turned out that at the first moment, the field hugs the target, but over time it expands and fills the entire corona — the outer part of the plasma cloud.

Comparison with calculations showed: the model correctly predicts how much magnetic field is generated, but poorly describes how it moves through space. So, we understand the physics of field generation well, but its "transport"—not yet. It's like knowing how much water you poured into a bathtub but not understanding where it flows.

Such experiments are a step toward controlled nuclear fusion. If we learn to accurately calculate magnetic fields, we can better confine hot plasma and prevent it from cooling. And that's the path to clean, almost limitless energy.