Neutron activation analysis (NAA) is a sensitive analytical technique used to determine the composition of materials. It involves irradiating a sample with neutrons, which causes certain elements to become radioactive. These radioactive isotopes emit gamma rays, which can be measured to identify and quantify the elements present in the sample. This method is widely used in various fields, including environmental science, forensic science, and archaeology. NAA is particularly valuable because it can analyze small sample sizes and detect trace elements, making it an essential tool for researchers and scientists in understanding material composition.