Can Protons or Positrons Flow as a Current?

[lufc88]

Instead of electrical current could there ever be a situation where protons or positrons are made to flow as a current?

 

[cepheid]

Instead of electrical current could there ever be a situation where protons or positrons are made to flow as a current?

Any flow of charge constitutes a current, and I think you might even call it an "electric" current, even if it doesn't consist of electrons.

In particle accelerators, two beams of high energy protons (confined by magnetic fields) are accelerated around a ring in opposite directions until they collide into each other. I'm not sure about a situation in which there is a positron current.

In a plasma (like the ionized gas in a fluorescent light tube or one of those Geiger counters), both the electrons and the positive ions flow under the presence of an applied voltage (they just flow in opposite directions). It's only in a solid (as opposed to gaseous) conductor that the positive ions are restricted to be in the crystal lattice and only the electrons are mobile. So a plasma is another situation where you have a flow of positive charges.