Development of a digital radiography system based on silicon microstrip detector

We are developing a digital radiography system based on double sided microstrip silicon crystal. The read-out system consists of a VLSI integrated circuit that has the following properties: low noise preamplification, pulse shaping, threshold discrimination. The current signals coming out of the integrated circuit are converted into TTL level signals by discrete component electronics. A Time-to-Digital-Converter+Transputer-based acquisition system reads the TTL signals and reconstructs the impact point of the incident photon. We made a study of the spatial resolution by measuring the Square Wave Resolution Function. To test the imaging capability of the system, we made some radiographs of low contrast (< 10%) phantoms. Moreover, an image of a small sample of bone tissue has been obtained by scanning technique (average contrast of the phantom is 20%).