Chroniton radiation is a by-product contaminant of the Romulan interphase generator developed in 2368. (TNG: "The Next Phase")

Chroniton torpedoes emit chroniton radiation. Exposure to this radiation has also been associated with time travel. (VOY: "Before and After") The Orb of Time, for example, created a massive surge of chroniton radiation, when it sent the USS Defiant back in time from 2373 to 2268. (DS9: "Trials and Tribble-ations")

When Kira Nerys was possessed by a Prophet on the Promenade of Deep Space 9, it was suggested that crew flood the Promenade with chroniton radiation. If they ramp up the chroniton levels slowly, the wormhole alien would be able to leave Kira's body without either getting hurt. (DS9: "The Reckoning")