  Atomic squeezing is studied for the case of large systems of radiating atoms,
when collective effects are well developed. All temporal stages are analyzed,
starting with the quantum stage of spontaneous emission, passing through the
coherent stage of superradiant emission, and going to the relaxation stage
ending with stationary solutions. A method of governing the temporal behaviour
of the squeezing factor is suggested. The influence of a squeezed effective
vacuum on the characteristics of collective emission is also investigated.
