Density and temperature diagnostics of solar emission lines from NeV/MgV and SiVII/MgVII Ions

We present NeV/MgV and SiVII/MgVII theoretical line intensity ratios as a function of electron densityN sub(e) and temperatureT sub(e). These are shown in the form of ratio-ratio diagrams, which should in principle allow bothN sub(e) andT sub(e) to be deduced for the emitting region of the solar plasma. We apply these diagnostics in the solar atmosphere, and discuss the available observations made from space. In most cases, however, we deduceN sub(e) andT sub(e) from the computed absolute line intensities in a spherically symmetric model atmosphere of the Sun. Possible future applications of this investigation to spectral data from the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO) are briefly discussed.