Anti-atoms with antiprotons (with a negative charge) at the center which are orbited by positrons (electrons with a positive charge).
Used as the energy source and as a means of propulsion by starships and as a warhead:
- In a starship main drive the tremendous energy density of antimatter is released by the reaction of matter/antimatter being converted into a hot plasma which is vented out to provide propulsion - the intent is the maximum conversion of matter into energy, not the total annihilation of matter by antimatter. The reaction also releases energy in the X-ray and gamma ray spectrum.
- An antimatter warhead utilizes matter/antimatter annihilation. About half of this energy is expressed as harmless neutrinos and muons, but the remainder creates an ultrahot plasma radiating across the electromagnetic spectrum including a deadly burst of high-frequency gamma radiation and high-speed neutrons. The gamma-ray flux can be strong enough to transmute some elements into radioactive isotopes.
The warhead is much smaller than a conventional nuclear weapon as the quantity of antimatter required is very small; however, it must be contained to prevent premature detonation.
- Antimatter is usually manufactured in orbit.
- Antimatter is stored as super-dense pellets - which have an effect on the local g-field.