5   Conclusions

A very large dataset has been collected, and a preliminary analysis is still ongoing. A large number of medium-class flares (GOES class C1 to M1) have been recorded, in some cases with full temporal coverage of the pre- and post-flare activity. The main features that appear to be common are:

• Active regions produce recurrent flares on all timescales. Some are associated with filament eruptions and/or CME's. Normally, the general plasma characteristics before and after the flare are very similar.

• The signatures of the X-ray GOES fluxes are normally traceable and have corresponding hot (T=8 MK) Fe XIX emission associated. This emission is at the beginning spatially confined and tends to diffuse on timescales of minutes to hours. Fe XIX precursor emission is seen in many cases.
• The Fe XIX emission is highly correlated with the YOHKOH SXT broadband images.
• The 1-5 MK AR emission does not appear to be dramatically affected by flares, if we except blue-shifts of tens of Km/s that are usually located at the base of the hot loops and that sometimes last for quite long (hours), and are probably associated with slow chromospheric evaporation.
• Post-flare TR brightenings are ubiquitous and show strong red- or blue-shifted emission (in general large non-thermal velocities).
• Electron densities in the TR brightenings are quite high, in the range 1-6 x 10¹¹ cm^-3.

The CDS instrument has a great potential for studying compact AR flares occurring on timescales of hours. It allows direct estimates of plasma temperatures, densities and velocities. However, the observed structures are very complex, and careful analysis of multi-wavelength observations, with the aid of extrapolations of the photospheric magnetic field is required.