Chronon energy, cronon energy, or chronon radiation (also known as time energy) was a form of radiation that was linked to temporal anomalies and time travel. It was carried by chronon waves. (AUDIO: Interstitial)
TARDISes released chronon energy (PROSE: Attack of the Snowmen) and Magnus Greel's arrival in the time cabinet in the 1800s via a zygma beam caused massive discharges of chronon radiation which flowed along the Earth's telluric currents, forming the Dragon Paths.
The segments of the Key to Time were traced by the chronon radiation they gave off. (PROSE: The Shadow of Weng-Chiang)
Similarly, those who travelled through time were left with traces of chronon energy, even if the travel was brief. (PROSE: Attack of the Snowmen)
The Fifth Doctor noted that both he and his TARDIS were "riddled" with chronon energy, enough to keep Kalu from being able to affect them. (AUDIO: Interstitial)
The Vist were capable of "smelling" time energy. (AUDIO: The Forbidden Time)
Time Lord bodies were apparently sustained by chronon energy, as the Sixth Doctor was weakened to the point of death when most of his chronon energy was lost during his confrontation with the Lamprey. (PROSE: Spiral Scratch)
The Ninth Doctor could smell it in the air, describing the scent as "bananas and ice cream". (COMIC: The Bidding War)
Weeping Angels fed on time energy created when they threw their victims into the past to live off of the energy of their "lost days." (TV: Blink, The Time of Angels/Flesh and Stone, The Angels Take Manhattan)
The Eleventh Doctor stated that pure, unrefined temporal energy is "the fire at the end of the universe". (TV: Flesh and Stone) Thanks to the Kovarian Chapter (TV: The Time of the Doctor) temporarily destroying the TARDIS, (TV: The Pandorica Opens) all of time and space was nearly destroyed by this; however, their blunder was corrected by the Doctor. (TV: The Big Bang)