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The application of a two-dimensional photon-counting detector based on a micro-pixel gas chamber (micro-PIC) to high-resolution small-angle X-ray scattering (SAXS), and its performance, are reported. The micro-PIC is a micro-pattern gaseous detector fabricated by printed circuit board technology. This article describes the performance of the micro-PIC in SAXS experiments at SPring-8. A dynamic range of >10(5) was obtained for X-ray scattering from a polystyrene sphere solution. A maximum counting rate of up to 5 MHz was observed with good linearity and without saturation. For a diffraction pattern of collagen, weak peaks were observed in the high-angle region in one accumulation of photons.

The application of a two-dimensional micro-pixel gas chamber (micro-PIC) to X-ray diffraction studies, and its performance, are reported. micro-PIC has a 10 cm x 10 cm detection area, and a fast-readout system for real-time X-ray imaging has been developed. Using the timing of each incoming X-ray measured by micro-PIC, continuous rotation photograph measurements were carried out for a 400 microm-diameter spherical organic crystal of Ylid (C(11)H(10)O(2)S), and then diffraction spots were successfully obtained within 2theta of 49 degrees. As a result, good internal agreement factors of 3.7% and 7.0% were confirmed among each of the symmetrically equivalent reflections for exposure times of 3700 s and 98 s, respectively.

A two-dimensional microstrip gas chamber (MSGC) with a 5 cm x 5 cm detection area has been developed. It has 254 anodes and 255 back strips, both with 200 micro m pitches. Using this MSGC, linear polarization of X-rays was successfully measured in the energy range 6-14 keV. In addition, the performance of the MSGC as an X-ray imaging polarimeter has been simulated using the EGS4 program (Electron Gamma Shower, Version 4) modified for this purpose. In this article, the results of both the polarization measurement and the simulation are reported.

A two-dimensional microstrip gas chamber (MSGC) has been developed with a 10 cm-square detection area and an ultrafast read-out system. The MSGC was made using multi-chip module (MCM) technology, and has a very thin substrate of 17 micro m and many anodes and back strips, both with 200 micro m pitches. The new read-out system, in which the hit addresses of the electrodes were sequentially encoded to the hit positions by a synchronous clock, handles data rates of up to 10(7) events s(-1) from MSGCs. This enables the acquisition of fast and sequential digital images. Furthermore, since the MSGC is a real photon-counting detector, the timing of the photons, to an accuracy of a few tens of nanoseconds, and energy can be recorded. Here, the performance of the MSGC system as a real-time area detector is reported, and the abilities of this system are discussed.

A high-performance data-acquisition system has been developed in order to obtain time-resolved sequential images from a two-dimensional microstrip gas chamber (MSGC). This was achieved using fully digital processing with a synchronized pipeline method. Complex logical circuits for processing large numbers of signals are mounted on a small number of complex programmable logic devices. The system is operated with a 10 MHz synchronous clock, and has the capability of handling more than 3 x 10(6) counts s(-1) for asynchronous events. The system was examined using a 5 x 5 cm MSGC and the recently developed 10 x 10 cm MSGC (1024 outputs); the anticipated performances were achieved.