Measurement of the properties of a flat-panel gas X-ray detector

Recently, large-area image detectors were investigated for X-ray imaging in medical diagnostic and other applications. In this paper, a new flat-panel gas detector for diagnostic X-ray imaging is proposed, and its characteristics are investigated. Research on flat-panel gas detectors is scarce, because of the difficulties of injecting gas against atmospheric pressure. So almost all gas detectors are designed as a chamber. We made a flat-panel sample by display technique (e.g. plasma display panel, field emission display, etc.). Transparent electrodes, dielectric layer, and MgO protection layer were formed in the front glass. Additionally, X-ray phosphor layer and address electrodes were formed in the rear glass. Dark current, X-ray sensitivity, and linearity as a function of electric field were measured to investigate the electrical properties. From the results, the stabilized dark current density and significant X-ray sensitivity were obtained. A good linearity as a function of exposure dose could be realized in a wide diagnostic energy range. These results mean that the passive matrix-addressed flat-panel gas detector can be used for digital X-ray imaging.