High-resolution solar flare x-ray spectra obtained with rotating spectrometers on the Hinotori satellite

High-resolution solar X-ray line spectra obtained with rotating crystal spectrometers on the Hinotori are presented. The wavelength ranges recorded by the two spectrometers are 1.72--1.95 A and 1.83--1.89 A. Resonances and satellites of Fe XXVI and Fe XXV, Kα and Kβ, are observed together with the spectral features from Fe XIX to Fe XXV. For an impulsive X2.2 flare that occured to 1981 April 2, time profiles of various line intensities, line widths, and plasma parameters are derived. The Fe XXVI Lα intensity is found to reach its maximum 1 minute earlier than the Fe XXV line and shows very similar time behavior to the smooth component of the hard X-ray burst. Electron temperature derived from the satellite-to-resonance line ratio for Fe XXVI is (33--36) x 106 K at the peak and considerably higher than the electron temperature derived from a similar line ratio for Fe XXV. Increases of electron temperatures and a decrease of the line width are found to occur with steady increases of the line fluxes and the smooth hard X-ray burst. The ionization equilibrium for the ions of FE XXVI, Fe XXV, and Fe XXIV, and discussed using the models of the ionization balance. We found large emission measure (5 x 1049 cm-3) and high density (3.6 x 1011 cm-3) for the Fe XXVI emitting plasma