Thalaron radiation

Thalaron radiation is a form of electromagnetic radiation in the tertiary EM band that was deadly to organic forms of life as it was capable of instantly killing such organisms with even small amounts of the compound.

Unlike gamma radiation, thalaron radiation did not bring about a mutative effect to a living organisms genome but rather destroys it through a form of necrosis. Once every cell has been exposed to the radiation, the once living being simply turns to ash and fractures.

The Vulcan people during the time of Surak, most notably Varekat of the Vulcan Space Institute, had attempted to experiment with this type of radiation in order to use it as a form of weapon to be used against rival factions, however, nothing came of the research at the time. This research would be recalled when the Exile fleet from Vulcan reached what would be the Romulan world of Remus. The planet possessed numerous ores that emitted different types of radiation and it was calculated that one of those could be thalaron radiation. (TOS novel: Vulcan's Soul Exiles).

The knowledge of such a type of radiation was only theoretical to Federation scientists, with the radiation being considered a form of biogenic weapon. The Romulan Star Empire government under Praetor Narviat experimented on banned thalaron radiation reseach with a Tal Shiar facility being constructed on a remote world for study of the implementation of a thalaron generator, however, new factions with the Imperial Senate stopped the project from reaching its final stage. (DS9 novel: Tales of the Dominion War In the Pale Moonlight).

Shinzon of Remus, a rising warrior within the Imperial Romulan Fleet and part of a failed experiment in replacing Captain Jean-Luc Picard of Starfleet, managed to defeat a Dominion occupation force at the Tal Shiar compound and save the thalaron generator for his own purposes. Working with Senator Tal'Aura, a small amount of thalaron particles were released into the Imperial Senate which resulted in their death and allow Shinzon to achieve the title of Praetor. He also installed the thalaron generator on his warship, the Scimitar which he planned to use against his ancestral homeworld of Earth but this plot failed. (TNG movie: Nemesis).