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Feng-Shou Zhang College of Nuclear Science and Technology

The 9th Japan- China Joint Nuclear Physics Symposium, Nov. 7-13, 2015, Osaka. Production cross sections for superheavy and neutron-rich nuclei. Feng-Shou Zhang College of Nuclear Science and Technology Beijing Normal University, Beijing, China Collaborators:

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Feng-Shou Zhang College of Nuclear Science and Technology

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  1. The 9th Japan- China Joint Nuclear Physics Symposium, Nov. 7-13, 2015, Osaka Production cross sections for superheavy and neutron-rich nuclei Feng-ShouZhang College of Nuclear Science and Technology Beijing Normal University, Beijing, China Collaborators: Long Zhu, Bao-An Bian, Hong-Yu Zhou, BNU, Beijing Zhao-Qing Feng, Gen-Min Jin, IMP, Lanzhou

  2. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

  3. JCNP2015，Nov. 8-13，Osaka 1.K.Morita,SHEresearchatRIKEN/GARIS 2.Z.G.Gan,Alpha-decayofthen-deficient isotopes215-217U 3.Y.Watanabe,Experimentalstudyofmulti- nucleontransferreactionsof 136Xe+198PtforKISproject

  4. Introduction By the end of 1940, Mayer and Jensen put up their model by a strong spin-orbit coupling of nuclear force, which can explains why nuclei with so-called magic numbers of protons and neutrons are particular stable. 1.Eugene Paul Wigner For contributions to fundamental symmetry principles in both nuclear and particle physics 2. Maria Goeppert-Mayer and Hans Jensen For their discoveries concerning nuclear shell structure The Nobel Prize in Physics1963 http://nobelprize.org/physics/laureates/1963

  5. single-particle levels in the nuclear shell model

  6. Limits of long-lived SHN ?

  7. n-rich exotic nuclei - transuranium

  8. n-rich exotic nuclei around Z～70

  9. Z=113 in RIKEN 36.75 MeV TOF 44.61 ns 30.33 mm 36.47 MeV TOF 45.69 ns 30.08 mm 70Zn+ 209Bi → 278113 + n 278113 CN 278113 CN a a 1st chain 11.68 MeV (PSD) 344μs 30.49 mm 11.52 MeV (PSD) 4.93ms 30.16 mm 23-July-2004 18:55 (JST) 274111 274111 a a 0.88+10.43=11.31 MeV (PSD+SSD) 34.3 ms 29.61 mm 11.15 MeV 6.149+5.003 (PSD+SSD) 9.260 ms 30.40 mm 270Mt 270Mt a a 10.03 MeV 1.136+8.894(PSD+SSD) 7.163 ms 29.79 mm 2.32 MeV (escape) 1.63 s 29.45 mm 266Bh 266Bh s = 78 fb a a 2nd chain 9.08 MeV (PSD) 2.469 s 30.91 mm 9.77 MeV (PSD) 1.31 s 29.65 mm 2-April-2005 2:18 (JST) 262Db 262Db preliminary 204.05 MeV(PSD) 40.9 s 30.25 mm 192.32 MeV(PSD) 0.787 s 30.47 mm s.f. s.f. J. Phys. Soc. Jpn73(2004)2593 From K. Morita’s talk in 2005 RIKEN-Garis: Thickness of target 0.48mg/cm2，Research period 170days

  10. Z=113 in Dubna

  11. * 297 294 118 a 118 1 _ + 11.80 0.53 MeV 290 March 19, 2005 0.85 ms 13.66 MeV 116 a 07:43 17.5 mm 2 10.80 MeV 286 0.1 ms a 114 17.0 mm 3 10.16 MeV 282 0.15 s 112 16.8 mm SF 202 (151+51) MeV 2.7 ms 16.9 mm Z=118 Dubna－DGFRS: 249Cf+48Ca294118+3n

  12. SHE in Lanzhou Z=110

  13. Nuclear physicists contributions a lot to producenew elements: Z=93-118

  14. Nuclear physicists contribution in future to 119 and 120 ? Z=2, 8, 20, 28, 50, 82, next ？ N=2, 8, 20, 28, 50, 82, 126, next？ Double magic nuclei: 4He, 16O, 40Ca, 56Ni, 132Sn, 208Pb, next ？

  15. Recent progress for production of Z=119 and 120 Based on the DNS model

  16. Z=120 A master equation for fusion dynamics

  17. Z=120 A combined DNS and advanced statistical models

  18. Z=119, 120 A dynamical potential energy surface—the DNSDyPES model

  19. Z=119, 120 A diffusion model

  20. Z=120 A Langevin equation for fusion dynamics

  21. Z=119, Z=120 The maximal production cross sections: pb L Zhu, WJ Xie, FS Zhang, Physics Review C 89 (2014) 024615

  22. Z=119, Z=120

  23. Z=119, Z=120 FRDM：50Ti+248Cf, ERC:0.186pb 54Cr+248Cm, ERC:0.062pb KTUY：50Ti+249Cf, ERC:6.57Pb 54Cr+248Cm, ERC:11.3Pb X. J. Bao, Y. Gao, J. Q. Li , H. F. Zhang *，PHYSICAL REVIEW C 91, 011603(R) (2015)

  24. Recent Exp by W. Loveland

  25. Outline 1. Introduction 2.Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

  26. From IQMD to ImIQMD Several key problems 1. Stability: Friction 2. Surface energy: Switch function 3. Structure (Shell, pair, …) : Shell model, 2-center Shell model, Deformed 2-center shell model Shell correction： force derived from the shell correction energy： Fusion barrier： BA Bian, FS Zhang, PLB 665 (2008) 314–317 ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106 ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 750 (2005) 232–244

  27. Deformed Two-Center Shell Model (DTCSM) Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

  28. Shell corrections for Magic numbersMoeller, Nix, Myers, SwiateckiNucl. Data Tables 59(1995)185 Epshell(82)=-5.5 MeV, Enshell(126)=-6.8 MeV Ep,nshell(50)=-5.1 MeV Ep,nshell(28)=-1.24 MeV Ep,nshell(20)=-3.6 MeV Ep,nshell(8)=-2.2 MeV Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

  29. DTCSM for coldfusion reaction Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

  30. Static fusion barrier for 40Ca /48Ca +40Ca/48Ca ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 750 (2005) 232–244

  31. ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106

  32. Capture cross sections 48Ca+208Pb/238U  224102,254112 exp: Dasgupta et al., NPA734, 148(2004) Nishio et al., PRL93, 162701(2004) ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106

  33. Outline 1. Introduction 2. Theoretical models 3.Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

  34. Dynamica Coulomb Barriers Dynamic barrier distribution for 36S +90Zr at 80, 85 MeV ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106

  35. 3.1 Effects of shell correction The shell corrections for the reactions 16O+208Pb, 204Pb L Zhu, J Su, WJ Xie, FS Zhang, Nuclear Physics A 915 (2013) 90-105

  36. 3.2 Incident energy dependence of fusion barriers L Zhu, J Su, WJ Xie, FS Zhang, Nuclear Physics A 915 (2013) 90 K Washiyama, D Lacroix, Phys. Rev. C78(2008) 024610

  37. 3.3 Isospin effects Symmetric isotope reaction systems ANi+ANi (A=48, 54, 58,64) The fusion barrier for the neutron rich system is lower than that of the proton rich system. The height of the barrier increase with decreasing N/Z, while the opposite behavior can be seen for the radius of fusion barrier

  38. 3.4 Orientation effects of fusion barriers Orientation effects for 16O+154Sm For the deformed reactions, the static deformation is important which can influence the fusion barrier distribution L Zhu, J Su, WJ Xie, FS Zhang, Nuclear Physics A 915 (2013) 90-105

  39. Physics behind from ImIQMD calculations and behaviors dynamical barriers • It’s expensive to use microscopic models • to calculate the exact evaporation residue cross section • 2.The mass asymmetry η, E*, potential pocketΔ R, orientation θ, are important to the fusion probability • 3. Need to use a phenomenological model

  40. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4.Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

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