Effects of nuclear orientation on fusion and fission in the reaction using 238U target nucleus
Japan Atomic Energy Agency, Tokai, Ibaraki
2 Laboratory of Nuclear Science, Tohoku University, Sendai 982-0826, Japan
3 Gesellschaft für Schwerionenforschung mbH, D-64220 Darmstadt, Germany
4 Institut für Kernphysik, Johann Wolfgang Goethe-Universität, D-60486 Frankfurt am Main, Germany
a e-mail: Josef Buchmann-Professor
Fission fragment mass distributions in the reaction of 30Si+238U were measured around the Coulomb barrier. At the above-barrier energies, the mass distribution showed a Gaussian shape. At the subbarrier energies, triple-humped distribution was observed, which consists of symmetric fission and asymmetric fission peaked at AL/AH ≈ 90/178. The asymmetric fission should be attributed to quasifission from the results of the measured evaporation residue (ER) cross-sections for 30Si+238U. The cross-section for 263Sg at the abovebarrier energy agree with the statistical model calculation which assumes that the measured fission cross-section originates from fusion-fission, whereas the one for 264 Sg measured at the sub-barrier energy is smaller than the calculation, which suggests the presence of quasifission.
© Owned by the authors, published by EDP Sciences, 2010