Published online by Cambridge University Press: 22 July 2013
One of the key aspects of the upcoming Ultra-Fast Flash Observatory (UFFO) pathfinder forGamma Ray Bursts (GRBs) identification is the UFFO Burst Alert & Trigger Telescope(UBAT). The scientific propose of UBAT is to detect and locate as fast as possible theGRBs in the sky. This is achieved by using a coded mask aperture camera scheme with a widefield of view (FOV) and selecting a X-ray detector of high quantum efficiency and largedetection area. This X-ray detector of high quantum efficiency and large detection area iscalled the UBAT detector. The UBAT detector consists of 48 × 48 Yttrium Oxyorthosilicate(YSO) scintillator crystal arrays and Multi Anode Photomultiplier Tubes (MAPMTs), analogelectronics equipped with ASIC chips, digital electronics equipped with Field ProgrammableGate Array (FPGA) chips, and a mechanical structure that supports all components of theUBAT detector. The total number of the pixels in the UBAT detector is 2304, and the totaleffective detection area is 191 cm2. We will present the design andconstruction, and performance of the UBAT detector including the responses of the UBATdetector to X-ray sources.