Feng-Shou Zhang College of Nuclear Science and Technology Beijing Normal University, Beijing, China Collaborators: Jingjing Li, Cheng Li, Peiwen Wen, Gen Zhang, Long Zhu, Bao-An Bian, Hong-Yu Zhou, BNU, Beijing Zhao-Qing Feng, Gen-Min Jin, IMP, Lanzhou Production cross sections for superheavy and neutron-rich nuclei The SINAP-CUSTIPEN Workshop, Dec , 2015, Shanghai

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

2. Maria Goeppert-Mayer and Hans Jensen For their discoveries concerning nuclear shell structure 1.Eugene Paul Wigner For contributions to fundamental symmetry principles in both nuclear and particle physics The Nobel Prize in Physics 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.

single-particle levels in the nuclear shell model

Limits of long-lived SHN ?

superheavy and n-rich nuclei - transuranium superheavy and n-rich nuclei - transuranium

Nuclear physicists contributions a lot to produce new elements: Z=93-118

RIKEN-Garis: Thickness of target 0.48mg/cm 2 ， Research period 170 days Z=113 in RIKEN preliminary Mt 266 Bh CN MeV (PSD) 344 μs mm MeV (PSD+SSD) ms mm MeV (PSD+SSD) ms mm 9.08 MeV (PSD) s mm MeV TOF ns mm 23-July :55 (JST)     1 st chain 262 Db MeV(PSD) 40.9 s mm Mt 266 Bh CN MeV (PSD) 4.93 ms mm =11.31 MeV (PSD+SSD) 34.3 ms mm 2.32 MeV (escape) 1.63 s mm 9.77 MeV (PSD) 1.31 s mm MeV TOF ns mm 2-April :18 (JST) 70 Zn Bi → n     262 Db MeV(PSD) s mm 2 nd chain s.f.  = 78 fb J. Phys. Soc. Jpn 73(2004)2593 From K. Morita’s talk in 2005

Z=113 in Dubna

_ 0.53 MeV 0.85 ms13.66 MeV 17.5 mm  March 19, :43 SF MeV 0.15 s 16.8 mm 202 (151+51) MeV 2.7 ms 16.9 mm MeV 0.1 ms 17.0 mm 1    2 3 Dubna － DGFRS: 249 Cf+ 48 Ca  n Z=118

SHE in Lanzhou Z=110

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

Z=120 A master equation for fusion dynamics

Z=120 A combined DNS and advanced statistical models

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

Z=119, 120 A diffusion model

A Langevin equation for fusion dynamics Z=120

The maximal production cross sections: pb L Zhu, WJ Xie, FS Zhang, Physics Review C 89 (2014) 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 Z=119, Z=120 X. J. Bao, Y. Gao, J. Q. Li, H. F. Zhang * ， PHYSICAL REVIEW C 91, (R) (2015)

superheavy and n-rich nuclei - transuranium superheavy and n-rich nuclei - transuranium

Recent Exp by W. Loveland

More references (before) 1.Kratz, Norris and Seaborg, Mass-yield distribution in the reaction of 84Kr(605MeV) +238U, PRL33(1974)502, 156 nuclides 2. Otto, Fowlwe, Lee, and Seaborg, Mass yield distribution in the reaction of 136Xe(1150) +238U, PRL36(1976)135, 131 nuclides 3. Schadel, Kratz, Ahrens, Bruchle, Franz, Gaggeler, Warnecke, and Wirth, Isotop distributions in the reactoin of 238U(1785)+238U, PRL41(1978)469, enhancement 4.Kratz, Bruchle, Folger, Gaggeler, Schadel, Summerer, and Wirth, Search for superheavy elements in damped collisions 238U(7.3MeV/u)+238U, PRC33(1986)504, cross-section limits 10pb 5. Shen, Albinski, Gobbi, Gralla, Hildenbrand, and Herrmann, Fission and quasifission in U-induced reaction, PRC36(1987)115, mass drift

More references (this year) 1.Kratz, Loveland, and Moody, Syntheses of trans-U isotops with Z=<103 in multi-nucleon transfer reactions, NPA2015 in press, 2.Watanabe et al, Pathways for the production of n-rich isotopes around N=126 shell closure, 136Xe(8MeV/u) +198Pt, PRL15(2015) Vogt et al, Light and heavy transfer products in 136Xe+238U multinucleon transfer reactions, PRC92(2015)024619, PRISMA+AGATA 4. Barrett, Loveland, et al, The 136Xe(Ecm=450MeV) + 208Pb reaction: A test of models of multi-nucleon transfer reactions, PRC91(2015)064615, 200 P+ T-like fragments ………………………..

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

Fusion barrier ： Shell correction ： From IQMD to ImIQMD 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 force derived from the shell correction energy ： 1. Stability: Friction 2. Surface energy: Switch function 3. Structure (Shell, pair, …) : Shell model, 2-center Shell model, Deformed 2-center shell model Several key problems

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

Shell corrections for Magic numbers Moeller, Nix, Myers, Swiatecki Nucl. Data Tables 59(1995)185 E p shell (82)=-5.5 MeV, E n shell (126)=-6.8 MeV E p,n shell (50)=-5.1 MeV E p,n shell (28)=-1.24 MeV E p,n shell (20)=-3.6 MeV E p,n shell (8)=-2.2 MeV Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

DTCSM for cold fusion reaction Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

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

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

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

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

Physics behind from ImIQMD calculations and behaviors dynamical barriers 1.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

The picture of synthesizing SHE: DNS model T DNS P ER CN SF neutrons Capture processDNS compounded Quasi fission Full fusion Evaporate nutreons

a phenomenological model W. Reisdorf, Z. Phys. A 300, 227 (1981)

The maximal production cross sections for Z=119: The maximal production cross sections for Z=120: pb Production cross sections of Z=119 and 120 L Zhu, WJ Xie, FS Zhang, Physics Review C 89 (2014)

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

The 2nd and 3rd exp. methods 2nd: large mass (charge) transfer process in DIC 3rd: Sophie Heinz (GSI, 2014): Probing the stability of superheavy nuclei with radioactive ion beams, 95 Rb(37,58)+ 209 Bi(83,126)  (120,184) exp. ISOLDE, CERN, 2016

DIC process Book ： Nuclear Multifragmentation ， F. S. Zhang & L. X. Ge, 1998, Science Press, Beijing

TKEL~  Z 2 TKEL increasing ，  Z 2 increasing

The master equation

when x approaches x’ ， one expands this eq around x’=x, up to the 2nd order of (x-x’) ， one gets Fokker-Plank eq

For the average value and its mean square deviation  x 2 That means the is proportional to v, and the mean square deviation  x 2 is also proportional to D

For target-like(Z=96) fragments, Transfer 3, 4, and 5 protons Exp. Data: Schadel et al., PRL48 (1982)852 For target-like(Z=82) fragments, Transfer 2, 4, and 6 protons Exp. Data: Kozulin et al., PRC86 (2012) Xe Pb, 514 MeV U Cm, 800 MeV

Yb ＋ U Transfer 7 protons, Eu 5 protons, Tb 3 protons, Ho 0 protons, Yb For un know n-rich nuclei A 63 Eu, A=165~ Eu, N=102, ~  b Eu, N=103, ~0.5  b Eu, N=104, ~10 pb Eu, N=105, ~ pb For projectile like 70+z Yb 106+N

2nd and 3rd exp. methods 2nd: large mass (charge) transfer process in DIC 3rd: Sophie Heinz (GSI, 2014): Probing the stability of superheavy nuclei with radioactive ion beams, 95 Rb(37,58)+ 209 Bi(83,126)  (120,184) exp. ISOLDE, CERN, 2016 Is it possible to use RNB to produce Z=120 ??? 4. Recent results for large mass (charge) transfer reaction and reaction induced by RNB

周长 : 500 m 磁钢度 : 34 Tm 束流累积 束流冷却 束流加速 BRing: Booster ring 周长 :180 m 能量 : 17MeV/u(U 34+ ) iLinac: Spectrometer linac 周长 :240m 磁刚度 : 13Tm 电子 / 随机冷却 双 TOF 探测器 电子靶 SRing: Spectrometer ring HIAF 布局 SRing-A SRing-B 离子 - 离子 Merging （ U 92+ ） 电子 - 离子碰撞 （将来升级 ） BRing Provided by Jiansong Wang in RIBLL1 worskhop

Long Zhu et al, PRC89(2014) PRC90(2014) JPG42(2015) Yb+ 238 U E c.m. = 600 MeV Possible exp by HIAF ?

5. Summary 1.Dynamical barriers are very important for the fusion reactions, a phenomenological method, including the contributions from mass asymmetry, potential pocket, orientation, is used 2.Through the reactions 48 Ca+ 252 Es and 48 Ca+ 257 Fm, the SHN Z=119 and Z=120 could be synthesized (0.2~0.3 pb), if enough amount of 252 Es and 257 Fm can be collected to make targets 3.Some other methods, such as the large mass (charge) transfer process and reaction induced by RNB, etc, are welcome, to try to synthesize super-heavy and n-rich nuclei Thank you for your attention