Gamma radiation was the most energetic form of electromagnetic radiation, encompassing the shortest wavelengths in the electromagnetic spectrum.
The Federation used gamma rays to re-crystallize dilithium, used in a warp core. This energy could be measured by gamma-ray spectrometer.
During a scan of Aldean DNA, Doctor Beverly Crusher was able to confirm that gamma ray exposure was not responsible for the Aldeans' sterility. (TNG: "When The Bough Breaks")
Wesley Crusher's sentient nanites could be killed with gamma radiation. (TNG: "Evolution")
The lateral sensors of the USS Enterprise-D could be set to detect gamma radiation. (TNG: "Silicon Avatar")
When the spaceborne species dubbed Junior accelerated, an internal buildup of gamma particles was registered. (TNG: "Galaxy's Child")
When Doctor Timicin tried to re-vitalize the sun Praxillus, one of the side affects was a seventeen hundred percent rise in gamma radiation levels. (TNG: "Half a Life")
The Crystalline Entity left behind a trail of antiprotons and gamma radiation. By using a gamma scan, the path of the creature could be detected. (TNG: "Silicon Avatar")
The Trialan sun gave off gamma bursts shortly before Meridian shifted from one dimension into another. This was an indicator of an anomaly in the sun's fusion cycle. (DS9: "Meridian")
The USS Rio Grande was exposed to high levels of gamma radiation in 2370 after it traveled near Orellius Minor. (DS9: "Paradise")
The damaged warp core of Tieran's Ilari starship leaked drive plasma and gamma radiation. (VOY: "Warlord")
A set of binary pulsars encountered by USS Voyager in 2374 emitted high levels of gamma radiation. (VOY: "Scientific Method")
Borg weaponry produces gamma radiation. The Brunali homeworld had residual gamma radiation due to numerous Borg incursions. (VOY: "Child's Play")