Theta radiation
- Radiation known to be extremely toxic to most living organisms
- Also commonly known as antimatter radiation (VOY: "Friendship One")
- Byproduct of warp drive operation (Star Trek: First Contact; VOY: "Night")
- Early-generations drives focused on containing radiation, disposing of waste afterwards, similar to early fission plants (Star Trek: First Contact; VOY: "Night")
- Later-generation drives use radiometric converters to absorb theta radiation, recycling it to generate energy in order to increase overall drive efficiency, reduce risk to crews (VOY: "Night")
- High concentrations disrupt subspace in local space, preventing generation of subspace fields (VOY: "Juggernaut")
- In small concentrations, occasionally used in radiation therapy procedures for particular microorganisms proving resistant to other treatments (ENT: "Bounty")