Scintillators for Precision y-Spectrometers

Abstract

The article analyzes the possibilities of using modern scintillators that provide a relative energy resolution along the y-line of 137Cs ER662keV ≤ 5%. Precision gamma spectrometers are relevant for use in technological processes of the nuclear industry, at nuclear power plants for monitoring the activity of air, waste water and adjacent areas, etc.
 Now 36 scintillation crystals are known that meet the above mentioned requirement. Of these, only 8 are produced by industry. Seven crystals are candidates for development in industrial production. The rest are hardly suitable for practical use due to the low light yield of LY (Cs2NaGdCl6:Ce, Tl2LiYCl6:Ce and TlCaCl3, for example). Eu-activated crystals have a high light output (LY = 60÷100 ph/MeV) and a low light output nonlinearity (NLY = 7÷10%) in a wide range of electron energies, which is extremely important for the spectrometry of “soft” y-radiation (ER662keV ≤ 10%). Due to the high self-absorption of light, these scintillators lose their advantages in the energy range Ey = 200÷3000 keV.
 The article shows that among the scintillators suitable for the simultaneous detection of gamma and neutron radiation, crystals containing 6Li are more preferable.