VERSATILE DOUBLE-CRYSTAL FIXED EXIT MONOCHROMATOR FOR X-RAY SYNCHROTRON-RADIATION

We describe a new monochromator that was designed and constructed for applications in x-ray scattering and extended x-ray-absorption fine structure experiments. The monochromator consists of two separate crystals of the same type. The monochromator covers a wide angular range from 58° to 5.1° which is equivalent to an energy range of 2.3-22 keV using Si 111 crystals. A constant offset of 1 in. is maintained between the incident white radiation and the exiting monochromatic radiation. The monochromator employs a simple mechanism to achieve this result. The monochromator is housed inside a stainless steel vacuum chamber and is currently operating in a high vacuum environment. The first monochromator crystal is water cooled in order to avoid temperature drifts due to the high heat load synchrotron radiation. This article presents the design details, characteristics, and data collected with this monochromator. © 1995 American Institute of Physics.