Does the Kibble mechanism operate in liquid He-4?

A rapid passage of liquid He-4 through the lambda (superfluid) transition i s expected (W.H. Zureck, Nature 317, 505; 1985) to result in the production of topological defects (quantized vortices) through the Kibble mechanism, the same process that is believed to have produced cosmic strings at the GU T phase transition of the early universe. But recent experiments (Dodd et a k, Phys. Rev. Lett 81, 3703; 1998) show that the density of vortices create d, if any, seems to be smaller than predicted by a factor of at least 100. Possible ways of improving the sensitivity of the experiment are discussed.