What is neutron activation analysis?

1 Answer
Aug 29, 2014

Neutron activation analysis (NAA) is a an analytical technique that uses neutrons to determine the concentrations of elements in a sample.

When a sample is bombarded with neutrons, a target nucleus captures a neutron and forms a compound nucleus in an excited state.


The compound nucleus rapidly emits γ rays and converts into a more stable radioactive form of the original element.

The new nucleus in turn decays by emitting β⁻ particles and more γ rays.

The energies of the γ rays identify the element, and their intensities give the concentration of the element.

This technique can be used to analyze about 74 elements. Up to 30 elements can analyzed simultaneously at levels ranging from 10⁻⁷ g to 10⁻¹⁵ g per gram of sample.


NAA can identify and quantify all the trace elements in a sample. It is used in chemistry, geology, archeology, medicine, forensic science, and many other areas.