Ray tracing of curved-crystal X-ray optics for spectroscopy on fast ion beams

A method of ray tracing is presented which allows a detailed analysis of the X-ray line profile observed with a curved-crystal spectrometer for both a stationary or a fast X-ray source. In particular, the effect of finite dimensions of crystal and source and their interplay with a finite velocity vector of the source is discussed for Johann and Johansson spectrometers. It is shown how some parameters cause distortions and shifts of the reflex and how far they can be resolved by using a two-dimensional position-sensitive X-ray detector. (orig.)