GAMMA ? RAY SPECTROSCOPY USING NAI(TL) DETECTOR

An attempted work had been made on the basic principle that when a radiation interactedwith the detector material, it was absorbing by the material and emitting flash of light, i.e, scintillation. The Thallium doped Sodium Iodide scintillation had been used. In that crystal the thallium acted as an activator. To measure the spectrum of several standard gamma emitters using NaI(Tl): (Thallium doped Sodium Iodide), scintillation counter coupled with modular electronics, multichannel analyzer and software. A given scintillation material was used to convert the energy of ionization into visible photons. The scintillation so produced may be directed to PMT (Photomultiplier tube) which convertedit into electrical signal. The amplitude of the signal was a measure of the incident gamma radiation energy. A Geirger counter merely determined count rates for radiation, gamma spectroscopy had ability to determine both the count rate as well as the energy of radiation. A detector could identify an unknown radioisotope by identifying features on the gamma spectrum and comparing them to known spectra. The spectra of different source would be measured. Those spectra analyzed and the features that distinguish them from other spectra identified. The gamma rays interact with matter by several processes. Some of those processes were photoelectric absorption, Compton scattering, pair production, coherent scattering, photonuclear reactions etc.