Antiproton Annihilation Propulsion

Some thought...

Hi Success Machine,

The collision of proton/antiproton pairs can yield tons of new particles, it is this collision that is used in large particle accelerators at Fermilab and CERN to create new particles (or create beams of other particles for further collisions).

There's one problem though, and that is the law of conservation of charge: if you annihilate/collide a proton/antiproton pair, then a particle/antiparticle pair has to be produced (charge violation has not been observed to my knowledge). For example, the following processes are permitted: (p+ = proton, p- = antiproton, e- = elektron, e+ = positron)

(p+) + (p-) = 2gamma (annihilation with light)
(p+) + (p-) = (e+) + (e-)

So if you would want the produced particles, such as positrons, as a trust, you would need a mechanism that would seperate both as soon as possible (before the positron/elektron pair can annihilate to gamma's again). This isn't essentially a problem (a few magnetic/electric fields can do that) but it will be hard to construct: the fields used to seperate the elektron/positron need to be at the location of collision, so you would need a mechanism to prevent the incoming proton/antiproton from also deflecting.

I think the best way to solve this would be to aim the incoming proton/antiproton beams in such a way, that the deflection caused by the fields directs the beam to a direct collision. That way the fields can be turned on all the time, and positive/negative particles would be seperated before they annihilate. All you need then are some extra fields to guide the particles to the engine's exit for thrust generation.


A way to beat the gamma ray problem wold be if the matter and antimatter are first accelerated to relativistic speeds. You'd have a linear partical accelerator, the reaction would take place at one end, the energy released being used for a further kick and power generation using electric fields. The gamma radiation back to the vessel would be redshifted to something of a more manageable wavelength.
Hi xvenomousx,

Well, once the particle/antiparticle pair has annihilated to radiation, it's energy is pretty "useless" for a spacecraft. That's why you should try to prevent annihilation by keeping the particle & antiparticle apart with fields.