1. Multinucleon Transfer Reactions – a New Way to Exotic Nuclei? Sophie Heinz GSI Helmholtzzentrum and Justus-Liebig Universität Gießen Trento, May 26 - 30, 2014

2. Synthesis of Exotic Nuclei Figure: courtesy R. Knöbel Multinucleon Transfer ? Fusion, Fragmentation and Fission

3. Deep Inelastic Transfer Reactions FUSION DEEP INELASTIC TRANSFER Nuclear Molecule Compound Nucleus Evaporation Residue (ER) FUSION-FISSION Fission Fragments σ ER = σ capture ∙ P prim ∙ P survival Evaporation Residue (ER) Fission Fragments Primary Transfer Products E* = E cm – TKE + Q

4. Population of nuclei along the N = 126 shell in transfer reactions 1 μb The small cross-sections of <1 μb require separation + single event detection 136 Xe + 208 Pb Theoretical Model Predictions → Application of neutron-rich projectiles and targets in the Pb region → Application of beam energies at the Coulomb barrier Myeong-Hwan Mun, G.G. Adamian et al., PRC 89, 034622 (2014). V. Zagrebaev, W. Greiner, PRL 101, 122701 (2008). A Ni + 198 Pt 1 μb DNS model adiabatic potentials

5. The Velocity Filter SHIP N beam ≈ 5·10 12 / s N detector ≈ 100 / s v ~ E/B 11 22 sf 33 E, T 1/2 Isotope identification via radioactive decays Separation and identification of heavy reaction products at SHIP 5 ms 15 ms ΔΘ = (0 ± 2)°; ΔΩ = 10 msr pulsed beam structure β−β− γ ZXZX Z+1 Y

6. Population of Transfer Products along N=126 identified isotopes target nucleus, 207 Pb The reaction 64 Ni + 207 Pb at 5.0 MeV/u studied at SHIP → Isotope identification via gamma spectroscopy in the focal plane of SHIP → identificaiton of isotopes with Z = 73 – 89 with cross-sections >10 μb

7. for neutron-rich nuclei: σ Transfer ≥ σ Fragmentation − SHIP exp.: S. Heinz, O. Beliuskina, proceedings of the ECHIC2013, Jour. Conf. Ser. 515, (2014) 012007. − [1] W. Krolas et al., Nucl. Phys. A 724 (2003) 289. Population of Transfer Products along N=126 Transfer and fragmentation cross-sections

8. Transfer and Fragmentation TransferFragmentation N beam 5 · 10 12 / s5 · 10 9 / s d Target 500 μg / cm 2 5 g / cm 2 angular efficiency<5% (SHIP)<50% (FRS) angular distributionup to ~50º (Coulomb barrier) few degree (relativistic energies) A, Z identificationα, β decaysE, ΔE, TOF, Bρ → Consideration on experimental conditions only applicable for nuclei with appropriate decay properties applicable for all nuclei experimental conditions are much more favourable in fragmentation reactions

9. Population of Transfer Products along N=126 Transfer and Fragmentation yields (at the target) N beam d Target efficiency Transfer Fragmentation 5 · 10 12 / s 5 · 10 9 / s 500 μg / cm 2 5 g / cm 2 < 5% (SHIP) < 50% (FRS) yield (Fragmentation) > 10 x yield (Transfer)

10. Population of N-rich Transuranium Isotopes Transfer reactions in 48 Ca + 248 Cm studied at SHIP → Transuranium nuclei are not reachable in fragmentation reactions identified at SHIP 48 Ca + 248 Cm (transfer), H. Gäggeler et al., PRC 33, 1983 (1986) 238 U + 248 Cm (transfer), M. Schädel et al., PRL 48, 852 (1982) Detection of new isotopes is restricted by missing identification techniques

11. Isotope ID via Precision Mass Measurements? Penningtrap mass selective T 1/2 > 100 ms m/Δm > 10 6 - 10 7 Time-of-Flight spectrometer broad-band T 1/2 > 10 ms m/Δm > 10 5 stopping cell (T. Dickel, W. Plaß et al., JLU Gießen) Isobar identification

12. ► Model calculations suggest the production of new neutron-rich nuclei in the region of Z > 92 and along N = 126 in transfer reactions → lack of experimental data ► Small cross-sections (< 1 μb) require effective separation + single event ID → lack of dedicated experimental setups → but: separators used in SHE research can be used for transfer studies ► Investigation of transfer reactions at SHIP: ▪ N = 126: 64 Ni + 207 Pb reactions → observation of n-rich isotopes with Z = 73 - 89 → σ Transfer ≥ σ Fragmentation but: fragmentation leads to much higher yields Summary ▪ Z > 92: 48 Ca + 248 Cm reactions → observation of n-rich isotopes with Z = 84 – 102 → region cannot be accessed in fragmentation or fusion reactions with stable beams ► main restriction is presently missing identification techniques for heavy transfer products