Development of MicroStrip Gaseous Chamber for Realtime X-ray Imaging Detector

The MicroStrip Gaseous Chamber (MSGC) was proposed in 1988 [1] as a new type of proportional gaseous detector providing an excellent position resolution. A very fine pitch (<200μm) of signal lines, which could be realized by printing several hundred of strips on a substrate using the Multi-Chip Module technology [2, 3],makes possible to satisfy almost all requirements for X-ray position detectors: a good position resolution of a few tens μm, and stable operation under a high luminosity X-ray (>10cps/mm). The MSGC is expected, therefore, to one of the next generation X-ray imaging detector for the third generation synchrotron radiation facility. We developed a new type MSGC system, which has not only anode strips but also back strips in orthogonal to each other on a poly-imide substrate. It is able to produce two-dimensional X-ray images by detecting both of the anodeand back-strip signals, while most of the existent MSGCs could give only one-dimensional position information for the anode-strips. We are also developing a novel high speed readout system based on the CPLD module in order to operate high counting rate events. This new MSGC will be used for small angle x-ray scat-tering (SAXS) experiments at RIKEN beam-line I (SR Structural biology), where the maximum x-ray intensity will be 10 photons/mm/sec at the detection part.