X-ray optics of a dynamical sagittal-focusing monochromator on the GILDA beamline at the ESRF

被引:291
作者
Pascarelli, S
Boscherini, F
D'Acaptito, F
Hrdy, J
Meneghini, C
Mobilio, S
机构
[1] IST NAZL FIS MAT, I-16153 GENOA, ITALY
[2] IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY
[3] CNR, I-00182 ROME, ITALY
[4] ACAD SCI CZECH REPUBL, INST PHYS, PRAGUE 18040, CZECH REPUBLIC
[5] SECONDA UNIV ROMA, DIPARTIMENTO FIS, I-00133 ROME, ITALY
[6] TERZA UNIV ROME, DIPARTIMENTO FIS, I-00146 ROME, ITALY
关键词
X-ray optics; dynamical diffraction; sagittal focusing; XAFS;
D O I
10.1107/S0909049596004992
中图分类号
TH7 [仪器、仪表];
学科分类号
0804 ; 080401 ; 081102 ;
摘要
The performance of a dynamical sagittal-focusing monochromator for hard X-rays is described. It consists of a flat first crystal and a diamond-shaped ribbed second crystal which is clamped by its central rib and dynamically bent by applying a force on its two apices. The system has proved to perform very well on the GILDA beamline at the ESRF. The horizontal acceptance varies with energy and with focusing geometry as predicted theoretically; :he total available horizontal fan of radiation (3.6 mrad) is in fact collected in the 1:3 geometry. The system is routinely run in a dynamical focusing mode for XAFS spectroscopy in the energy range 5-30 keV with Si(311) crystals, with a constant spot size FWHM similar to 1 mm on the sample and without degradation of energy resolution or reproducibility. Using simple geometrical considerations we calculate the variations of the horizontal profile of the reflected beam during rocking-curve scans in different focusing geometries and find them in agreement with observed ones. Not only is this is a practical aid in alignment but it illustrates the X-ray optics of sagittal focusing in an elegant way.
引用
收藏
页码:147 / 155
页数:9
相关论文
共 14 条