activation analysis

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A method for analyzing a material for its component chemical elements by bombarding it with nuclear particles or gamma rays and identifying the resultant radiations.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun chemistry Any of several similar techniques in which a subatomic particle or gamma ray is captured by a nuclide to form a second stable nuclide which is then measured.