The magneto-hydrostatic field in the region of Zebra patterns in solar type IV dm-bursts

A very general dynamic model for the interpretation of Zebra patterns (Mollwo, 1983) traces back the observed dynamic spectra to a warm helical electron beam travelling through the magnetically confined plasma of a coronal condensation. Supposing a two-dimensional field configuration it is shown that Zebra patterns with two crossing stripe systems supply an adequate number of parameters to calculate the most essential field quantities for the emitting region. The magnitude of the magnetic field B is in accordance with the results of potential field calculations (cf. Dulk and McLean, 1978). Four events with very different values of the frequency drift, of the Zebra stripes among them one with a typical braided Zebra pattern, yield rather similar results. Special variants of the mechanism may account for fiber bursts and perhaps also type III b-bursts. Considerations on the continuation of the field configuration beyond the region of the Zebra pattern yield some basic approaches to treat the field of an unipolar sunspot.