gamma ray vs gamma radiation

gamma ray and gamma radiation both are nouns.

Word	Noun	Adjective	Verb	Adverb
gamma ray	Yes	No	No	No
gamma radiation	Yes	No	No	No

As nouns, gamma ray and gamma radiation are synonyms defined as:

gamma ray and gamma radiation: electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength

gamma ray (noun)	gamma radiation (noun)
electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength	electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength