X-ray spectroscopy of solar flares

After a brief review of the nature of the solar corona, the X-ray output of solar flares is discussed in some detail with particular reference to emission line excitation mechanisms and to the information that can be obtained about the flare plasma from studies of the intensities, profiles and wavelengths of these lines. The X-ray crystal spectrometers on the NASA Solar Maximum Mission spacecraft are described and the interpretation of the spectra obtained with these instruments is discussed.