Reflective zone plate as a tool for characterizing a laser-plasma source of soft X-rays

A grazing-incidence reflective zone plate is designed for operation at a wavelength of 135 Å in the first diffraction order, at a wavelength of 67.5 Å in the second order, and so on. A spectrometer with a reflective zone plate with a flat field in the 125–235 Å rang is proposed. Using numerical ray tracing, the spectral image of a point source is calculated at wavelengths of 135 and 135.1 Å, as well as 125, 125.1, 130, 130.1, 140, 140.1, and 145, 145.1 Å. It is shown that the spectral resolution in the flat field region exceeds 10³, and the spatial resolution in the crossed direction at the selected wavelength of 135 Å is no worse than 1 μm. The reflective zone plate is an effective tool for diagnosing the spatial and spectral parameters of a laser-plasma soft X-ray source.