APPARATUS FOR X-RAY DIFFRACTION IN ULTRAHIGH VACUUM.

The authors have constructed an instrument that allows a solid surface, prepared with established ultrahigh vacuum (UHV) procedures, to be examined by X-ray diffraction. The greatest advantage of X-ray diffraction as a surface probe lies in the high angular resolution attainable with a synchrotron source. Therefore, compromising the precision of the diffractometer by isolating the sample from the vacuum chamber on a bellows and sliding teflon seal has been avoided. A manipulator, built into the sample stage, ensures great flexibility of surface analytical and preparatory techniques.