Abstract : The CCR-flows give the simplest example of a semigroup of endo-morphisms of the *-algebra of the set of all bounded linear operators in the Fock-space over L^2(R_+), which enjoys the continuous tensor-product decomposition property and thus produces the simplest example of the so-called product systems. Using a “sto-time” in the Fock space one constructs a large class of new ” CCR-flows” ,each carrying its own “product-system” . Similarly,isometric evolutions in Fock space can also be stopped with respect to a given stop-time .