Simulation study of plasma display panel with GMD structure for x-ray imaging detector

Screen-film based radiography has been rapidly substituted by digital radiography(DR), recently. Generally, thin-film-transistor(TFT) with amorphous silicon(a-Si) or amorphous selenium(a-Se) have been used for DR x-ray imaging systems. Another flat panel display method, plasma display panel (PDP) has a similar structure to conventional gas type radiation detectors and can be manufactured with lower cost than TFT-based detector panels. The motivation of this study is to develop cost effective DR detector using PDP. In order to apply PDP technologies into gaseous detector for x-ray imaging, we modified the pixel structure and optimized the materials inside of the PDP panel. To maximize the signal intensity, we re-designed the panel structure based on gas microstrip detector(GMD) and estimated the performance of proposed detector using Monte-Carlo simulation method. Signal intensity of gaseous detector is determined by the amount of ionization and avalanche effect. Each process has been simulated by Geant4 and Garfield, respectively. Four types of gas mixtures and various electric fields have been explored. The results show that more Xe portion helps to create more ionization electrons and electric field which has been applied between anode and cathode strips was dominant factor for avalanche. In this study, we adopted the GMD structure into plasma display panel based x-ray detector. Also, we verified the effectiveness of proposed structure, quantitatively.