Imagine a puff of cigarette smoke suddenly turning into a sphere and rolling around. That’s what happens with plasma becomes a plasmoid — it forms a structure that contains itself and moves as a unit. We finally have pictures of plasmoids as well as our first simulation of them. Here’s why that’s a big deal.
Plasma is a state of matter that strips atoms of their electrons without the electrons actually “going” anywhere. Instead, the positive ions and negative electrons swim around together in a kind of soup without reconnecting. Several things can create plasma, including high heat and strong magnetic fields. Plasma isn’t too exotic. It’s in neon lights, but it is a high energy substance, so when a lot of extreme hot plasma is created, it can be tough to contain.
Tokamaks, large donut-shaped devices, both create and contain plasma. These structures use coils of wire to create magnetic fields which both kick off the formation of plasma, and contain it. The plasma inside these is hot enough that physical materials alone couldn’t keep it in check. Unfortunately, the coils of metal and bar in the center limits the size of the tokamak.
That might change. The “cored apple” structure you see at the very top is a tokamak, and the vague little bubbles are plasmoids. We know plasmoids form in the atmosphere and in the sun. They’re also one of the candidates scientists are considering as the phenomenon responsible for ball lightning.
The picture of actual plasmoids formed in a tokamak is cool, but the achievement of simulating the plasmoids is more important. A team of scientists, led by Fatima Ebrahimi at the Princeton Plasma Physics Laboratory, managed to create a simulation of a plasmoid that behaves the way the plasmoid caught on camera in a tokamak behaved. Understanding how plasmoids move under certain conditions might be the first step to a new way of creating nuclear fusion, or a supervillain who uses ball lightning to rule the world. Either way, it’s interesting.
[Source:Physical Review Letters]
Top Image: Left,Image: Fatima Ebrahimi, PPPL; Right, Nishino-san, Hiroshima University. Second Image: Max-Planck Institut für Plasmaphysik.