Ulf Torkelsson wrote in message ...
Thomas Smid wrote:



First of all, the corona can not be considered to be separately in a
hydrostatic equilibrium as it is virtually collisionless due to to low
plasma density. As explained on my page
http://www.plasmaphysics.org.uk/research/sun.htm, the corona (and the
solar wind) is produced by those few plasma particles that do not
suffer any inelastic collisions in the photosphere and thus have the
full gravitational energy of about 1keV.

So you are suggesting that the corona is made up of particles that pass
from the centre of the Sun to the corona without suffering any collisions.
If that was the case we would also see the Sun emitting gamma-rays rather
than optical light.


Well, the corona is also emitting x-rays and for this you need
obviously particle energies in the keV region. The particles come from
just below the photosphere and it is only a very small fraction (less
than 10^-15) that can penetrate the photosphere without being stopped
by inelastic collisions.