Now and again, everyone gets a chance to show the true depths of their ignorance, and I suspect this is my chance, but you know what? I don’t really care. I have some good ideas as well as dumb ones, and sometimes it is too hard to know which is which. I freely admit that my physics is very rusty. However….
Plasma is essentially a highly ionised gas; lots of ions and free electrons. It conducts electricity so is ideally suited to magnetic confinement. You make a current in it, and use magnetic field interaction with that current to hold it in place.It can also hold a decent charge overall, positive or negative. That means it interacts electrostatically as well as magnetically. Electromagnetics is all one big happy field anyway.
A strong magnetic field can be made that encompasses the plasma magnetically without it needing to be surrounded by a solid object. Let’s do a thought experiment.
Start off with a sealed ball and make a small hole in it, put an electric coil around the hole, send some current through it, and make a field around that hole to stop plasma escaping. Ditto the opposite side of the ball, so now you have a tube with plasma in it, albeit a fat tube with narrow ends. Gradually make the hole diameters bigger and bigger, and the tube shorter and less curvy. Eventually you will have more or less a fat disk of plasma. The relative dimensions of the disk will depend on the intensity and control of the magnetic field, the ionisation of the plasma and any currents you make in it.
With some good physics and engineering, adequate sensing and a decent control system, I reckon it should be possible to make reasonable sized disks of plasma. So, make two of them. Put the two disks reasonable close and face to face. Arrange them so that the electric currents in the plasmas run in different directions too. If they are both similarly charged overall they will repel electrostatically and their internal magnetic fields will also interact, but the managed applied magnetic fields could stop them deforming too much. Add more disks, and we have plasma plywood. Let’s call it plasma-ply for lack of a better word.
I can’t calculate how thin this plasma-ply could be made. I suspect that with future materials such as graphene and room temperature superconductors, future remote sensing and advanced computer control systems, they could be pretty damned good. If you try to deform one of these disks, it would resist, because the magnetic and electrical interactions would create force to keep it in place. We have another name for that. We call it a force field and we see them in every space opera. If the surrounding coils and other stuff is just a think ring, as you’d expect, you’d have a round window. Maybe a smallish window, but you could use a lot of the coils to make a big window in a honeycomb structure.
So we can bin the word plasma-ply and start using the words we already have. We will have force fields and plasma windows. Plasma will be the new glass, and an important 21st century building material.