New sandwich type detector module and its characteristics for dual x-ray baggage inspection system

Using two phosphor screens based on Gd₂O₂S:Tb and linear array 16 channel photodiodes, new dual-energy detector was designed and fabricated for X-ray baggage inspection system. By simulation, we derived optimum detector structure and proved that the combination of Lanex regular for LED and Lanex fast-B for HED with 1.5 mm copper filter in the HED had the same performance as a commercial dual-energy detector. After fabrication of our own designed linear array photodiode and data acquisition, X-ray test was performed at the condition of 140 kVp /0.8 mA and Z-map was derived using two phantoms of aluminum and acryl. As a result, the phosphor screen coupled detectors showed better uniformity property and similar separation ability as the commercial one provided.