  Various field strength correlators are investigated in the maximal Abelian
projection of pure SU(2) lattice gauge theory. High precision measurements of
the colour fields, monopole currents, their curls and divergences allow for
detailed checks of the dual superconductor scenario. On this basis, we perform
a Ginzburg-Landau type analysis of the flux tube profile from which we derive
the size of the penetration length, LAMBDA = 0.16(2) fm, and coherence length
of the monopole condensate wave function, XI = 0.27(3) fm. The ratio of these
numbers is KAPPA = LAMBDA/XI = 0.59(13) which is below the value 1/SQRT(2)
where type II superconductivity sets in.
