Quasifission processes inCa40,48+Sm144,154reactions

Mass-energy and angular distributions of fission fragments for the $^{48}\mathrm{Ca}+^{144,154}\mathrm{Sm}\ensuremath{\rightarrow}^{192,202}\mathrm{Pb}$, $^{40}\mathrm{Ca}+^{154}\mathrm{Sm}\ensuremath{\rightarrow}^{194}\mathrm{Pb}$ reactions have been measured. Fusion suppression and the presence of quasifission at energies near and below the Coulomb barrier have been observed for the reactions with the deformed target $^{154}\mathrm{Sm}$. In the case of the spherical $^{144}\mathrm{Sm}$ target no evidence of quasifission has been found. Quasifission cross sections have been extracted from total fission-like events by analysis of their mass and angular distributions.