أرشيف الوسم : activation

A technique in which a neutron, charged particle, or gamma photon is captured by a stable nuclide to produce a different, radioactive nu­clide which is then measured. The technique is specific, highly sensitive, and applicable to almost every element in the periodic table. In neutron activation analysis (NAA), the most widely used form of activation anal­ysis, the sample to be …

activation 1 the action or process of rendering an atom, molecule, or other substance reactive or more reactive, whether physicochemically, chemically, or biochemically. 2 the process of rendering material artificially radioactive: radioactivation. See radioactivation analysis. 3 the initial changes in an ovum during fertilization, covering the periodfrom first contact with a sperm to dissolution of the nuclear membranes. 4 the …

An analytical technique that can be used to detect most elements when present in a sample in milligram quantities (or less). In neutron activation analysis the sample is exposed to a flux of thermal neutrons in a nuclear reac­tor. Some of these neutrons are cap­tured by nuclides in the sample to form nuclides of the same atomic number but a …