A LOW-COST AND FLEXIBLE DOUBLE-CRYSTAL MONOCHROMATOR FOR AN X-RAY BEAMLINE

This work designs and implements an inexpensive and simple double-crys tal monochromator, which yields a high performance ar a bending magnet x-ray beamline. A primary feature of the proposed monochromator is th at the offset between the incident and monochromatic exit of the x-ray beam can be adjusted to cover a wide energy range with a short X-Y tr aveling stroke. Such a short range of X-Y strokes fan reduce the monoc hromator's overall size and, also, increase the stability of motions, Meanwhile, in this monochromator, instead of using a complicated hardw are linkage mechanism, a software program is developed to effectively control the X-Y stage for positioning the second crystal in a fixed ex it configuration, alleviating mechanic motion errors to maintain the p arallelism of the two crystals. The entire software control mechanical linkage offers a relatively inexpensive and simple assembly monochrom ator that is mon flexible than the commercially available one. (C) 199 8 American Institute of Physics. [S0034-6748(98)00403-1].