Plasma Rail Railgun

Railguns! They are full of electricity, and that can be a problem. It seems that there are two varieties of projectile: ones that conduct by themselves, and ones that have some foil on the back: the foil turns into plasma (a plasma armature) and that conducts the electricity, driving the projectile forward.

A problem is that the rails suffer. Stuff gets blasted off of them from electrical arcing. They must be replaced, which is slow and spendy.

I propose that the rails be replaced with bolts of lightning. Often one sees lightning travel a given path in the sky several times. It is because the lightning has ionized a path which must remain for a second or two. Instead of solid rails, in the plasma railgun there will be two wires, contained within a ceramic bore. The initial pulse of electricity will ionize the wire into plasma, which will serve to conduct the electricity. The plasma armature of the projectile will mix with this plasma to some degree and conduct between the rails. Rail ablation will not be a problem because the rails will already be ablated.

After each firing, new rails in the form of new wires will be pulled down the bore, which will be cheap and fast.

It seems that another big problem with railguns is arcing between the solid rails, which hurts them and wastes energy which should be driving the projectile. To get an arc one must have a conductive medium - vacuum is a perfect insulator. If the ceramic bore contains a vacuum, the same forces which drive the projectile (and push the rails apart) should also push the charged plasma rails apart, so that stray wire ions do not contaminate the vacuum and allow an arc.

Eventually there will be a lot of metal electroplated on the inside of the bore. A stiff bristled brush on the end of a big stick might be used to clean it out.