  We consider the expectation value of a magnetic flux loop in the immediate
forward light cone of collisions of heavy nuclei at high energies. Such
collisions are characterized by a non-linear scale Q_s where color fields
become strong. We find that loops of area greater than ~2/Q_s^2 exhibit area
law behavior, which determines the scale of elementary flux excitations
("vortices"). We also estimate the magnetic string tension, sigma_M = 0.12
Q_s^2. By the time t ~ 1/Q_s even small loops satisfy an area law. We describe
corrections to the propagator of semi-hard gluons at very early times in the
background of fluctuating magnetic fields.
