The fine structure of a nanoflare-heated corona

Implications of the conjecture that the solar corona is heated by small-scale events (nanoflares) are examined. It is shown that even if these nanoflares are small-scale (heating areas much smaller than 1 arc sec²) and impulsive, the corona may still be rather homogeneous. In particular, the filling factor (defined as the ratio of the coronal volume radiating in X-rays and EUV to the total volume) can easily be of order unity. Future experimental determination of the filling factor could prove useful in estimating the volume of coronal material that is heated during nanoflares.Work performed at Beam Physics Branch, Plasma Physics Division, Naval Research Laboratory, Washington, D.C., U.S.A.Mailing Address: Code 6790, NRL, Washington, D.C. 20375, U.S.A.