  Space scientific exploration is becoming the main battlefield for mankind to
explore the universe. Countries around the world have successively launched
various space exploration satellites. Accurate calibration on the ground is a
key factor for space science satellites to obtain observational results. In
order to provide calibration for various satellite-borne detectors, several
monochromatic X-rays facilities has been built at National Institute of
Metrology, P.R. China (NIM). These facilities are mainly based on grating
diffraction and Bragg diffraction, the energy range of produced monochromatic
X-rays is (0.218-301) keV. The facilities have a good performance on energy
stability, monochromaticity and flux stability. Monochromaticity of all
facilities is better than 3.0%, the stability of energy is better than 1.0%
over 8 hours, and the stability of flux is better than 2.0% over 8 hours. The
calibration experiments of satellite-borne detectors, such as energy linearity,
energy resolution, detection efficiency and temperature response can be carried
out on the facilities. So far we have completed the calibration of two
satellites, and there are still three satellites in progress. This work will
contribute to the development of X-ray astronomy, and contribute to the
development of Chinese space science.
