Experimental Measurement and Calibration of Celestial Bodies with High Resolution Soft X-ray Radiation

In recent years, using the atomic data measured by experimental devices to explain astronomical observational puzzles (including weak lines radiation, calibration of diagnostic characteristic lines ratio and anomalous lines flux ratio) has made great strides. In order to measure the high-resolution soft X-ray spectra of highly charged iron ions, an ultra-high vacuum flat field spectrometer is designed and built on the National Astronomical Observatories of the Chinese Academy of Sciences(NAOC) EBIS-A platform. In single-slit mode, the spectrometer uses 1 200 grooves/mm varied line-spacing diffraction grating in the wavelength range of 11.5-19.8 nm. With the same working principle of the electron beam ion trap, Heidelberg-EBIT ultraviolet spectrometer experiment data based on Chianti database is analyzed in the spectral region from 11.5 to 14.5 nm. First, a linear regression model is established to calibrate the offset of the peak position of line strength caused by the experimental system. Then the soft X-ray spectra of Fe ions in various ionization stage simulated by the collision radiation model identifies wavelengths of Fe VIII and Fe XIX-XXIII line radiation in experimental measurement. And the present simulations satisfactorily reproduce the measured spectra. Furthermore, blend lines of Fe XIX and Fe XX, which is weaker than the transition line of Fe XXIII, are found at 13.292 5 ±0.101 78 nm but the observed spectra has not resolved these weak lines. Therefore, the following experimental measurement can take the predicted results as a reference to test the performance of the spectrometer.