For use in a vacuum.

The gun strips hydrogen atoms and accelerates the electrons one way on a ring magnet and the protons in the other direction (not in the same path but using as much of the same hardware as possible). It then discharges both beams in succession (electrons, then protons).

This idea comes from reading George O. Smith's The Complete Venus Equilateral (one of my favorite SF books).

In the story he pointed out several problems with using an electron beam as a weapon.

  1. As you fire the beam you acquire a high positive charge (the electrons have to come from somewhere).
  2. The negative charge that the target acquires will start to deflect the beams of subsequent shots.
  3. Beam dispersal.

The twin beam seems to have a few advantages:

  1. The charge of both the firing ship and the target remains neutral.
  2. Any negative charge picked up by the faster moving electron beam will, in a small way, add to the accuracy of the heavier and slower proton beam. The overall neutral effect on the target will not significantly affect succeeding shots.
  3. Beam Dispersal. Well, no real help here that I can see except that the spread out electron beam can paint the target and help the proton beam focus a tiny bit more of the near misses onto the target.
  • $\begingroup$ Plus the beam dispersal. Plus I have a feeling that by the time it got to the target it'd mostly be a bunch of hydrogen again, but I dunno. en.wikipedia.org/wiki/Particle-beam_weapon#Beam_generation talks about just straight up shooting beams of hydrogen atoms, by accelerating protons then having them capture electrons on the way out. $\endgroup$
    – Jason C
    Commented May 10, 2017 at 0:54

1 Answer 1


Is it feasible?

Yes. Both these 'guns' exist already. Cathode ray tubes have electron beams, while some types of radiation therapy use proton beams. Scaling these up is a matter of engineering, so they are no more or less realistic than giant laser cannons in space.

Is it a good weapon?

This is a question you didn't ask, but maybe should have. The biggest weakness of anything electrically charged as a space weapon is that charged particles are the only thing that we can reasonably create a defensive shield against. There aren't 'shields' to stop lasers, there aren't 'shields' to stop kinetic particles or missiles, but a magnetic field can certainly deflect moving charged particles.

Also, beam dispersion will be much worse in a charged particle weapon than it would in a laser, leading to reduced range. Finally, if you can accelerate a few kg of protons and electrons to an appreciable fraction of $c$, then why not accelerate a few kg of steel to that speed and let it one-shot whatever vessel you are hurling it at?


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