[author=”jamesr” date=1254411336]

Just because there is a current doesn’t mean the pinch is strong enough to collapse the filaments enough to heat them significantly as done in Z-pinch machines. The large current is spread out over a huge volume, so the local current density at any one point is still small.

The ions & electrons accelerated into the magnetic loops above the area of the sunspot do indeed reach a high velocity/temperature and so the electrons emit bremsstrahlung radiation at x-ray wavelengths. And I suppose there could be a very small chance of fusion for the most energetic ions, but it’s hardly a significant phenomena.

Flares and CMEs are spectacular and involve the transfer of huge amounts of energy from the magnetic field to the plasma surface of the sun, but in no way are they related to fusion.

Certainly, sunspots are very large, but so do circular electric currents (1,000,000,000,000 Amperes for middle size circular sunspots). The density of circular electric currents is approximate 5,000,000 amperes/meter along axial direction of eyewalls of sunspots.
Sunspots differ from Z-pinch devices, Z-pinch devices use pulse kind electric currents and use just electromagnetic forces, but sunspots are stable, the circular electric currents in eyewalls of sunspots are stable, and plasmas in eyewalls of sunspots are compressed by a centripetal force and electromagnetic forces. Hollow cylindrical plasmas with large circular electric currents cannot become sunspots if they do not pinch.
Some hydrogen bombs with black mushroom clouds certainly have pinch processes too. J. L. Tuck of England has achieved pinch processes in his Perhapsatron devices in early 1950s; the discharge electric currents in his devices are very small.

Who accelerate and heat electrons and ions in the magnetic loops above the sunspots?

You think that the huge amounts of energy of solar flares and CMEs come from magnetic fields of the sun, but my question is: where do these huge amounts of energy of magnetic fields of the sun come from?