Evaluations of ZnO based α-ray imager

In the present paper, we describe the development of an α-ray imaging detector based on a ZnO single crystalline scintillator and a position-sensitive photomultiplier tube (PSPMT). The ZnO crystal was grown by the hydrothermal synthesis method with 2-inch-φ in diameter. The ZnO specimen was polished out to be 0.5 mm in thickness. After optically coupling with PSPMT, the crystal was irradiated with ²⁴¹Am α-ray for evaluation of both spatial resolution and pulse height spectrum. Using the charge center of the gravity method, two-dimensional α-ray images were successfully obtained. The efficiency of the energy window in terms of imaging quality was also examined.