Portal de Periódicos da CAPES

PbO as direct conversion x-ray detector material

2004; SPIE; Volume: 5368; Linguagem: Inglês

10.1117/12.533010

1996-756X

M.E. Simon, R. A. Ford, Anthony R. Franklin, S Grabowski, Bernd Menser, G. Much, A. Nascetti, Michael Overdick, Martin J. Powell, Detlef Wiechert,

Digital Radiography and Breast Imaging

A flat X-ray detector with lead oxide (PbO) as direct conversion material has been developed. The material lead oxide, which has a very high X-ray absorption, was analysed in detail including Raman spectroscopy and electron microscopy. X-ray performance data such as dark current, charge yield and temporal behaviour were evaluated on small functional samples. A process to cover a-Si TFT-plates with PbO has been developed. We present imaging results from a large detector with an active area of 18 × 20 cm 2 . The detector has 1080 × 960 pixels with a pixel pitch of 184 μm. The linearity of detector response was verified. The NPS was determined with a total dark noise as low as 1800 electrons/pixel. The MTF was measured with two different methods: first with the analysis of a square wave phantom and second with a narrow slit. The MTF at the Nyquist frequency of 2.72 lp/mm was 50 %. We calculated first DQE values of our prototype detector plates. Full size images of anatomic and technical phantoms are shown.