A comparative study of Nal (TI) and HPGe Detectors with Respect to Detectors in Terms of Detection Efficiency and Energy Resolution

Abstract

   The main aim of this search is to compare between a sodium iodide (NaI) detector (scintillator), which is thallium (TI) doped coupled to photomultiplier and a hyper pure germanium detector (semiconductor)(HPGe) in terms of efficiency and energy resolution. Both were used to measure the energy sensitive of Gamma ray in which the gamma ray is analyzed using scintillation and a multichannel analyzer. In addition, hyper pure germanium was used in this experiment to identify the known source.

In term of energy resolution, HPGe detector found to have superiority of energy resolution over NaI detector. This can be seen in Cs-137 at 661KeV where the full width of half maximum (FWHM) was 42.8KeV with using NaI detector and 10.17 KeV with using HPGe.

In term of efficiency, it is clear that NaI detector has much more efficiency than HPGe detector. For example, the intrinsic photopeak efficiency of Na-22 at 511 keV was 12.75% with using NaI detector and 5.11% with using HPGe .