Role of barrier penetration in complete fusion of heavy ions

The relevance of tunneling in determining the cross section for complete fusion is explored. The classical model with frictional forces is used for the determination of the trajectory of two heavy ions up to the classical turning point. The penetrability of the barrier is calculated quantum mechanically. It is shown that the so calculated transmission coefficient differ from the sharp cut-off approximation, but yield cross section for complete fusion which are not significantly different from the cross section neglecting quantum mechanical effects.