A bending magnetic in SPring-8 provides X-rays in a wider energy range. At the bending magnet beamline, however, the photon density decreases with a distance from the source point of the magnet because of dispersion. For the experiments, X-rays must be focused on the sample position by a bender, which can efficiently collect the dispersed beam. The focusing device is called as a sagittal focusing bender.
Sagittal focusing has been required at a standard beamline of the bending magnet in Spring-8 as well. However, a ready-made bender is not available for X-rays of a wide energy range from the bending magnet in SPring-8. Thus an original bender used for an energy range of 8 - 150 keV has been developed (Fig. 8-15). The new device can bend the second Si crystal (Fig. 8-16) of a double-crystal monochromator into ideally cylindrical shape without introducing any deformation in the crystal.
Good results have been obtained in the performance test where the inclined 111, 511 and 733 reflections have enabled us to focus high energy X-rays up to 30 keV, 100 keV and 150 keV, respectively, quite efficiently (Fig. 8-17). In the whole energy range one order of magnitude increase in the photon density has been achieved without a decrease in the energy resolution. Now the new sagittal focusing benders have been installed in SPring-8 as standard monochromators. In BL14B1 (JAERI beamline), the bender is effectively used for the structure analysis of non-crystalline materials. |
