After reading this, you might decide to give particle beams their rightful place alongside lasers as a means of transmitting power, propelling spacecraft or dealing damage at long distances.
This post focuses on particle beams deployed and used in space. All claims and calculations here are based on paper and studies referenced through links throughout. The first sections focus on the hard science behind particle beams and the performance achieved by existing accelerators.
We then move on plausibly extrapolated performance and then to informed speculation on how they can be designed and used before ending on topics most relevant to sci-fi authors and worldbuilders.
A particle beam is a stream of electrons, ions or neutral atoms that have been accelerated to a high velocity by an accelerator from a particle source.
Particle beams are used in a huge variety of ways. Everything from electron microscopes to cancer treatment involves a particle beam. A common example of a particle accelerator is a medical X-ray. It produces a beam of electrons that emit X-ray light when they hit a metal target.
This technology was also a focus of the Strategic Defense Initiative back in the 1980s, which culminated in an accelerator-equipped satellite being launched into space to test the performance of particle beams at different altitudes.
To describe the characteristics of particle beams, we could use standard units such as velocity in meters per second or particle energy in joules. However, the typical beam is highly relativistic (90%+ the speed of light or 0.9 C) and each particle has a very small amount of energy (a hundredth billionth of a joule or less)