annihilation radiation

Also found in: Encyclopedia, Wikipedia.

an·ni·hi·la·tion ra·di·a·tion

the radiation resulting when a positron from beta-positive decay comes to rest. It encounters an electron, and the two particles annihilate each other and convert their rest mass into two 0.51-MeV gamma rays emitted in exactly opposite directions. See: pair production.
Mentioned in ?
References in periodicals archive ?
Although the source of the annihilation radiation is debatable, there is no dearth of candidates in the crowded environs of the galactic center.
Matter falling onto such a compact object would produce low-energy gamma rays, which in turn would generate the positrons needed to produce the annihilation radiation.