Focusing X-ray spectrograph with spatial resolution and uniform dispersion

A new focusing X-ray spectrograph with spatial resolution and uniform dispersion (FSSRUD) is proposed. Uniform dispersion (i.e., the linear dispersion is a constance, or in other words, the X-rays are dispersed on the detector with uniform spacing for every wavelength) can be realized by bending the crystal of a spectrograph into a special shape. Since the spatial coordinate of the spectrum obtained by the FSSRUD varies linearly with X-ray wavelength, it is very convenient for identification and processing of the experimental data. In addition, an optimized spectrograph capability can be achieved by customizing the bent shape of the crystal and other spectrograph parameters to satisfy the given requirements of routine measurement. The spectrograph capability is first analyzed using a ray tracing method, the principle to design the shape of the crystal for the FSSRUD is then presented and the numerical evaluations are used to validate its effectiveness.