it defiantly looks like a physics project, universities have glass blowing departments, you would not get that oblong easy to break side piece with a commercial product, or a military product for that matter, they want things to ship nicely
I think its something to let plasma go through the side piece and maybe measure it with something, maybe a current probe?
that glass structure is used for convection often, or circulation, its common in a passive circulation oil melting point tester (the circulation is a temperature control, a passive flow network) and a dean stark apparatus. Can it be something for looking at plasma turbulance/dynamics? You can also heat the side tube. not sure what that would do, its very interesting. I think if you put a flame on that side tube and there was gas inside it would start going around in a circle, at least if it was normal gas

always wanted to work on that kind of stuff