ANGLE CALCULATIONS FOR A 2-RAY DIFFRACTOMETER(2 SURFACE X)

Angle calculations are presented for a new type of diffractometer, whi ch has two degrees of freedom for the sample and two degrees of freedo m for the detector. The sample and detector motions are mechanically u ncoupled. This geometry is used to implement a surface diffractometer and the corrections necessary to extract integrated intensities in two of the most useful modes are presented. The relative merits of this g eometry and further extensions to it are discussed. Experimental data, showing the existence of an interfacial microstructure at the Si/SiO2 interface, are also presented to illustrate the advantage of this geo metry.