Effect of thermo-chemical treatments on the luminescence and scintillation properties of CaWO4

in this work, we investigated the influence of thermal annealing in different atmospheres on the luminescence and scintillation properties of CaWO4. Luminescence and luminescence excitation spectra were examined using VUV synchrotron radiation. Thermal treatment causes change of the defect subsystem of the crystal, resulting in the alteration of the spectral dependences. The most obvious effect is the relative change in the intensity of the defect emission band which is excited below the fundamental absorption edge 4.7 eV. Studies of the scintillation kinetics and light yield carried out over a temperature range 8-300 K showed that former does not change upon the treatment, in contrast to the intensity of scintillations. It is found that similar to 50% increase of the scintillation response can be achieved for CaWO4 samples annealed in hydrochloric acid. (c) 2007 Elsevier B.V. All rights reserved.