Temperature dependence of α/γ-ratio of GSO(Ce) scintillator

We measured temperature dependence of alpha/gamma-ratio of three sample pieces of Ce 0.5 mol% doped Gd₂SiO₅ crystalline scintillator, which are cut from different ingots and have a dimension of 24times24times5 mm³. The temperature is controlled by a heat bath within plusmn0.5 K at +20, 0, and -20 degrees of Celcius. By using intrinsic activity of ¹⁵²Gd 2.14 MeV alpha-ray, it is irradiated uniformly inside the scintillator. To determine alpha/gamma-ratio precisely, we measured input energy and pulse height linearity between 60 keV and 511 keV, at three temperature conditions. Then, we measure the alpha-ray response of the scintillator by a passive rejection any outer backgrounds by Pb and Sn blocks. As a result, alpha/gamma-ratio of 0.5 mol% Ce doped GSO is turned out to be ~0.175, and it showed a gradual temperature dependence of ~0.4 keV/K.