Development of the high sensitive detector for the time-resolved measurement of the X-ray small angle scattering of the biological material in solution

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The small-angle analysis is a powerful method to understand the structure of the molecule, in the sense of the shape, size and so on. Generally, the intensity of the scattering is very weak, and the high sensitive detector is necessary to observe the intensity accurately. In the present project, we have developed the new X-ray detector suitable for the small-angle scattering experiment. The imaging plate, which was developed by Fuji photo Co. Ltd. and is utilized for the single crystal diffractometer, was installed in the new detector. The plate was 115x190mm in size and was rolled cylindrically on the drum. One direction of the plate is for the scattering angle of the data, and the other is along the elapsed time for the time resolved measurement. The interval of the data along the drum was varied by changing the rotating speed of the drum from 440 to 0 rpm.. The pixel size for reading the plate was 0.1mmx0.1mm, and 4.5MB data were observed per plate were transfered to the computer th … More rough the high speed ADC. The data in the whole plane was measured to estimate the variation dependent on the place of the plane. The accuracy was estimated to be below 3%. The feeding phenomenon was found to take the serious problem for the time resolved measurement, because the relative intensity was not estimated correctly inspire of the splendid data for each measurement. The analytical interpretation of the observed data showed that the fading was approximated by exp(-bt^<1/2>).The computer controls the detector through the RS-232C, and saves the data to the disc through the SCSI interface. The observed data can be displayed on the monitor display. The X-ray was focused with a nickel-coated mirror and the stopped flow cell was applied for the time resolved measurement as a sample holder of the protein solution. The program for the analysis of the small angle scattering were also installed on the computer. Although the basic data for the time-resolved structural studies were obtained, the accuracy of the analysis is not known exactly. The further studies will prove the ability of the new detector. Less