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Various fundamental characteristics of Y2O3 ceramics, such as optical transmittance, reflectivity, absorption coefficient, refractive index, and dielectric constant, were investigated. Furthermore, in order to evaluate the possible application of this material as γ-ray scintillator, other radiation responses, like the α-ray excited emission spectrum, the γ-ray excited pulse height spectrum, the light yield, the nonproportionality, the energy resolution, and the γ-ray excited scintillation decay curves were obtained. The light yield of Y2O3 ceramics was evaluated in about 1.13 times higher than that of Bi4Ge3O12 (BGO):Ce single crystals and was estimated in 9300 photon/MeV. The nonproportionality measurements showed a good proportionality. The scintillation decay curve could be fitted by an exponential function characterized by a fast component of about 34 ns. [ABSTRACT FROM AUTHOR]

A microfocus x-ray tube with multiple targets and an electron gun with a focal spot size of 10 μm in diameter has been developed. The electron gun contains a LaB6 cathode and an Einzel lens. The x-ray tube can be operated at 50 W (50 kV, 1 mA) and has three targets, namely, Cr, W, and Rh on the anode that can be selected completely by moving the anode position. A focal spot size of 10 μm in diameter can be achieved at 0.5 mA current. As demonstration of the usability of a multiexcitation x-ray tube, the fluorescence x-rays have been measured using a powder specimen mixed of TiO2, Co, and Zr of the same quantity. The differences of excitation efficiency have clearly appeared according to the change in excitation source. From the results discussed here, it can be expected that the presented x-ray tube will be a powerful tool in microx-ray fluorescence spectrometers and various x-ray instruments. [ABSTRACT FROM AUTHOR]