Quantal Diffusion in Heavy-Ion Collisions

Abstract

We investigate the quasi-fission reactions in the basis on the Stochastic Mean-Filed (SMF) approach that provides a microscopic and quantal description of the multi-nucleon exchange mechanism.  In deep-inelastic heavy-ion collisions, colliding ions stick and move together for a long time. During this contact time many nucleons exchange between projectile and target nuclei, and the composite system then separate in two main primary fragments without forming a compound nucleus. Quasi-fission is a non-compound nuclear process in deep-inelastic heavy-ion collisions and the multi-nucleon exchange mechanism in the quasi-fission reactions is important. We calculate the quantal transport coefficients for heavy-ion collisions at bombarding energies below their fusion barriers and determine the primary fragment mass distributions. Quantal calculations are compared with the experimental data.

Keywords

• Multinucleon transfer,quasi-fission reaction,stochastic mean-field theory

References

1. C. Simenel, Particle-Number Fluctuations and Correlations in Transfer Reactions Obtained Using the Balian-Ve´ne´roni Variational Principle, Phys. Rev. Lett. 106, 112502 (2011).
2. V. E. Oberacker, A. S. Umar, and C. Simenel, Dissipative dynamics in quasifission, Phys. Rev. C 90, 054605 (2014).
3. K. Sekizawa and K. Yabana, Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in the 64Ni + 238U reaction, Phys. Rev. C 93, 054616 (2016).
4. S. Ayik, A stochastic mean-field approach for nuclear dynamics, Phys. Lett. B 658, 174 (2008).
5. S. Ayik, B. Yilmaz, O. Yilmaz, A. S. Umar, and G. Turan, Multinucleon transfer in central collisions of 238U + 238U, Phys. Rev. C 96, 024611 (2017).
6. S. Ayik, B. Yilmaz, O. Yilmaz, and A. S. Umar, Quantal diffusion description of multinucleon transfers in heavy-ion collisions, Phys. Rev. C 97, 054618 (2018).
7. B. Yilmaz, S. Ayık, O. Yilmaz and A. S. Umar, Multinucleon reactions in 58Ni+60Ni and 58Ni+60Ni in a stochastic mean-field approach, Phys. Rev. C 98, 034604 (2018).
8. J. Y. Roynette, et. al., On the time scale of 40 Ca+40Ca strongly damped reactions, Phys Lett B67, 395 (1977).

9. E. Williams et. al., Exploring zeptosecond quantum equilibration dynamics: from Deep-inelastic to fusion-fission outcomes in 58Ni+60Ni reactions, Phys. Rev. Lett. 120, 022501 (2018).
10. E. M. Kozulin, et. al., Shell effects in fission, quasi-fission and multinucleon transfer reaction, J. Phys, Conf. Ser. 515, 012010 (2014).