Fundamental properties of YAP Imager

Two-dimensional pixel detector, called “YAP Imager”, was designed for SPring-8 high flux synchrotron radiation facilities in high energy X-ray or γ-ray region. It is based on YAlO3:Ce crystals (YAP) with wavelength shifting fibers readout. The sensitive area of the imager is 132×132 mm2 and it is composed of an array of 1×1×6 mm3 YAP pillars. To supply two-dimensional readout two fiber layers (Kuraray B1(4 0 0)) with 128 fiber each are fixed at the top and bottom of the crystal array in orthogonal directions and optically connected with 8+8 H6568 (Hamamatsu) 16-anodes PMs. The obtained performances of the YAP Imager allow one to get a reliable imaging digital device without geometrical distortions with a spatial resolution close to 1 mm and ∼30% detection efficiency in 100 keV energy range.