Feasibility study of a plasma display-like radiation detector for X-ray imaging

In this study we have investigated a 2-dimensional gas type detector based on plasma display technology as a candidate for the flat-panel radiation detector. By using the Garfield code, the dependence of X-ray absorption and multiplication on gas composition, cell gap and electric field were examined. Considering the simulation results, three prototype detectors were designed and fabricated. The performance of these detectors was evaluated by measuring the collected charge density, dark current density and sensitivity. The collected charge had the highest value at a condition when Xe 100% and 2.8 mm gap was 108.8 nC/cm $^{2}$ at 1000 V. The dark current of the same detector was varied from 0.0095 to 0.10 nA/cm $^{2}$ and about a fourth of the dark current density of a-Se based detector was at the bias range of 100–1000 V. The sensitivity of Xe 100% and 2.8 mm detector was 0.20 nC/mR·cm $^{2}$ at 0.36 V/um. It is about a tenth lower than that of a-Se based detector at 10 V/um.