system
Given the following post, respond as if you're commenting on Reddit:
human
Is it possible to scale down a linear accelerator for it to fit into a spacecraft to power it by firing particles out of the other end?

I was looking at methods of propulsion in space and I was wondering if this was possible.
gpt
Yes - it's called an ion thruster or ion drive. It requires very little propellant, but quite a lot of power. This makes them most ideal for accelerating small probes in space. You can't provide the thrust to, say, launch from Earth or accelerate a large probe, but you can provide a small amount of continuous acceleration for a very long time, because you can continuously power the drive without using very much fuel. So the idea is that you can use this to get probes across the solar system quickly and efficiently.

A few missions have started to use ion thrusters in space, but it's still quite new and not extremely widespread.