Spallation reaction versus heavy-ion fusion: Fission excitation functions as a fundamental probe of presaddle nuclear dissipation

作者：Ye, W.^*; Tian, J.

来源：Physical Review C, 2015, 91(6): 064603.

DOI：10.1103/PhysRevC.91.064603

• HOT NUCLEI
• 10.6 MEV/NUCLEON
• PRESCISSION NEUTRONS
• COMPOUND NUCLEI
• CROSS-SECTIONS
• QUASI-FISSION
• DYNAMICS
• EVAPORATION
• DECAY
• COLLISIONS

Due to nuclear dissipation, fission cross sections drop with respect to standard statistical model predictions. Using the stochastic dynamical model of fission, we calculate the drop of fission cross sections, sigma(drop)(f) , as a function of presaddle dissipation strength (beta) under two contrasting initial conditions for produced Th-224 compound nuclei: (i) high excitation energy but low angular momentum (available in spallation reactions) and (ii) low excitation energy but high angular momentum (available in heavy-ion fusion). We find that the former type of conditions not only significantly increases the influence of friction on fission cross sections but also substantially enhances the sensitivity of sigma(drop)(f) to beta. Our findings suggest that on the experimental side, to accurately obtain information of presaddle friction strength with fission excitation function, it is optimal to choose the spallation reaction approach induced by energetic protons as a way to populate excited nuclear systems.

• 出版日期2015-6-5
• 单位东南大学