Fusion Dynamics for Hot Fusion Reactions revealed in Quasielastic Fusion Barrier Distributions
ORAL
Abstract
In order to clarify the fusion dynamics for hot fusion reactions, we measured the excitation functions on quasielastic (QE) scattering cross sections σQE for 22Ne+248Cm, 26Mg+248Cm, and 48Ca+238U systems. In contrast to previous QE fusion barrier distribution studies which measured the recoiled projectile nuclei at backward angles (θlab ∼ 170◦), this work obtained successfully the σQE for l = 0 by measuring the target nuclei recoiling into forward angle employing the gas-filled-type recoil ion separator GARIS. The QE fusion barrier distribution DQE were successfully extracted, and compared with coupled-channels calculations. The calculation results clearly shows that the DQE values are strongly affected by the deformation of the target nucleus and influenced by vibrational and rotational excitations of the colliding nuclei. Comparing the peak of the evaporation residue cross sections σER with the experimental average Coulomb barrier height B0, we found that the peaks appear well above the B0 in the barrier distributions. This indicates that the σER values are enhanced at the energy which corresponds to a compact collision geometry with the projectile impacting the side of the deformed target nucleus.
*248Cm material was provided by the U.S. DOE Isotope Program.
–
Presenters
-
Taiki Tanaka
- RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan
- RIKEN