NaI（T1）およびCSI(T1）のッ線発光特性と微視的計算

摘要

Inorganic crystalline scintillators are widely used as y-ray detectors. Intensive efforts have beenmade to investigate their light output non-linearity with respect to incident y-ray energies. Although thecode EGS5 (Electron-Gamma shower) can trace the electron-photon transportation and calculate energydeposit of γ-rays into a matter, it cannot predict light outputs from the crystalline scintillators. In thepresent work, we have incorporated the scintillation process to the code EGS5 by the help of thescintillation efficiency dL/dx described as a function of the electron linear energy transfer. It has made thelight output estimation possible for typical scintillation crystals, NaI(Tl) and CsI(Tl). Calculated lightoutputs were compared with measured data of a wide energy range of y-rays from 31 up to 1274 keV.Moreover, responses to the higher energy y-rays up to about 30 MeV were also investigated by using thelaser-Compton back scattering method. The calculation prescription developed presently has appeared togive reasonable accounts to experimental data.