Production of cold target-like fragments in the reaction ofCa48+248Cm

Yields for isotopes of Rn through Pu have been measured in the reaction ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ ${+}^{248}$Cm at an energy of 248–263 MeV (1.04–1.10 times the Coulomb barrier). Despite the low bombarding energy, high and essentially constant integral yields of about 1 to 2 mb for the elements Rn through U were observed. There is evidence that these nuclides are produced with little excitation energy.