Luminescence and Scintillation Properties of NaI:In Crystal

Single crystals of NaI activated with 0.02, 0.05, 0.1, and 0.5 mol% indium (In) have been grown with a two-zone vertical Bridgman furnace. The luminescence measurement of the crystals is carried out under the excitation of X-rays and photoluminescence (PL). Under X-ray excitation, the emission has broad bands peaking at 450 and 535 nm. The maximum radioluminescence of the crystal is obtained for NaI:0.1 mol% In. The pulse height spectra of the crystals are measured under 662 keV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula>-rays excitation from a Cs-137 source. The absolute light yields of the crystals are calculated by comparing the 662 keV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula>-rays photopeak with that measured for reference CsI:Tl and the indium-doped NaI crystals. The maximum light yield of ~42000 photons/MeV is found for NaI:0.5 mol% In.