  The variety of morphologies in flux patterns created by thermomagnetic
dendritic avalanches in type-II superconducting films is investigated using
numerical simulations. The avalanches are triggered by introducing a hot spot
at the edge of a strip-shaped sample, which is initially prepared in a
partially penetrated Bean critical state by slowly ramping the transversely
applied magnetic field. The simulation scheme is based on a model accounting
for the nonlinear and nonlocal electrodynamics of superconductors in the
transverse geometry. By systematically varying the parameters representing the
Joule heating, heat conduction in the film, and heat transfer to the substrate,
a wide variety of avalanche patterns is formed, and quantitative
characterization of areal extension, branch width etc. is made. The results
show that branching is suppressed by the lateral heat diffusion, while large
Joule heating gives many branches, and heat removal into the substrate limits
the areal size. The morphology shows significant dependence also on the initial
flux penetration depth.
