3-D Medipix: A new generation of X-ray detectors

The need for more efficient, more radiation tolerant sensors with better spatial and temporal resolution is ubiquitous. The drive for this comes from the ever more demanding high-energy physics experiments and synchrotron light sources where current technology is struggling to meet demands. Moreover, the developments in semiconductor detectors, as a result of academic research, are now being employed in areas such as medical imaging. In turn, such applications have their own very diverse and challenging requirements. The new ''3-D'' detector architecture, first proposed in 1997 [IEEE Trans. Nucl. Sci. 45(3) (1998) 751], has significant advantages over standard planar technology in a wide range of applications, e.g. in high-energy physics, synchrotron radiation detection and medical imaging. In 3-D detectors, unlike standard planar technology, the electrodes, as illustrated in Fig. 1, traverse the detector bulk. A 64x64 pixel 3-D detector designed for read out using a Medipix1 chip has been fabricated in silicon. The sensors have been characterised and the initial test results are presented in this paper