14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Formation, separation and detection of evaporation residues produced in complete fusion reactions R.N. Sagaidak Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Russian Federation 1.Fusion probability and survivability as main values that determine the heavy ER production cross section in HI reactions 2.Fusion probability in reactions with a different entrance-channel mass asymmetry 3.Survivability and macroscopic fission barriers derived with the statistical model analysis of ER cross section data obtained in very asymmetric projectile-target reactions 4.Experimental approaches to the separation and detection of ERs produced in HI reactions 1 14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS

The ER production cross section in the framework of different models Capture (barrier passing) CS Fusion Probability Survival Probability Measured Calculated with SSM P fus =1 for very asymmetric projectile-target combinations (SSM, no fusion suppression) P fus <1 for nearly symmetric massive projectile-target combinations (fusion suppression) Can we estimate P fus for nearly symmetric massive projectile-target combinations empirically? 2

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Extraction of CN-fission events from fission data with the decomposition of FF angular distributions integrated over masses and energies (B.B. Back’s approach): P CN =σ CN /σ cap 3 R. S. Naik et al., PRC 76, (2007) P fus from experiment (reasons)?

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS P fus experimentally obtained in reactions leading to the less fissile 202 Pb * CN G.N. Knyazheva et al., PRC 76, (2007); A.M. Stefanini et al., EPJA 23, 473 (2005); R.N. Sagaidak, EPJWC 21, (2012) The decomposition of fission fragment mass- angular and TKE distributions The comparison of ER cross sections with those obtained in a very asymmetric reaction implying no fusion suppression 4

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Comparison of the ER production in the 16 O+ 186 W and 48 Ca+ 154 Sm reactions leading to the 202 Pb * CN 5

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Why P fus < 1 in nearly symmetric combinations of fusioning nuclei? R. N. Sagaidak et al., PRC 68, (2003) GLDM of G.Royer & B.Remaud, NPA 444, 477 (1985) Potential energy surface calculated in the (Z,N)-plane for contact configurations with the expression for the proximity energy: R. Moustabchir & G. Royer, NPA 683, 266 (2001). R.N. Sagaidak, EPJWC 21, (2012) 6

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS The description of experimental ER cross sections for very asymmetric combinations of fusioning nuclei in the framework of barrier passing and statistical models (HIVAP) Barrier passing model (P fus ≡ 1) ● Coupling to various entrance channels – via the radius (barrier) fluctuations σ(r 0 )/r 0 generated using a Gaussian distribution with the mean value r 0 and width σ(r 0 ) ● The exponential nuclear potential with varied V 0 and σ(r 0 )/r 0, fixed r 0 =1.12 fm and d=0.75 fm ● The WKB approximation for transmission coefficients of partial waves penetrating the barrier Statistical model approximations ●Intrinsic level density only with the shell damping energy E D = 18.5 MeV ● The expression of W. Reisdorf for the macroscopic level density parameters in the fission and evaporation channels of the CN decay ● ER and fission cross section calculations adjusted with the LD barrier scaling using a scaling parameter k f as a main fitted parameter: ● Calculations of ground-state shell correction ΔW gs (a difference between empirical and LD masses), excitation and separation energies with empirical masses 7

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Macroscopic fission barriers derived with the SM analysis of ER cross section data obtained in very asymmetric combinations leading to Rn, Ra, Fr and Th nuclei R.N. Sagaidak, EPJWC 21, (2012) 8

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Production of At nuclei in the 12 C Au fusion-evaporation reaction 9

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Production and fission of Po and At nuclei in the 3,4 He + Pb,Bi fusion-evaporation and fusion-fission reactions R.N. Sagaidak, JPCS 580, (2015) 10

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Macroscopic fission barriers and shell corrections for Po and At nuclei 11 R.N. Sagaidak & A.N. Andreyev, PRC 79, (2009) R.N. Sagaidak, JPCS 580, (2015)

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Experimental approaches to the separation and detection of ERs 12 THE LNL ELECTROSTATIC DEFLECTOR (ED) S. Beghini et al., NIMA 239, 585 (1985) SLIDING SEALED TARGET CHAMBER TWO PAIRS OF CONDENSOR PLATES TOF-E (MCP + SSBD) Energy - TOF matrix obtained for the reaction 48 Ca+ 154 Sm, at E lab =208 MeV and θ lab =0 ◦ A.M. Stefanini et al., EPJA 23, 473 (2005) Nearly symmetric combinations Very asymmetric combinations leading to α-radioactive nuclei – detection of α-particles of ERs implanted into SSBD

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS Experimental approaches to the separation and detection of ERs 13 Peculiarities of the experiments with LNL ED R.N. Sagaidak et al., LNL Annual Report 2014 R.N. Sagaidak & A.V Yeremin, NIMB 93, 103 (1994) R.N. Sagaidak et al., LNL Annual Report 2014 R.N. Sagaidak & A.V Yeremin, NIMB 93, 103 (1994) R.N. Sagaidak et al., LNL Annual Report 2014 R.N. Sagaidak et al., NIMA 700, 111 (2013)

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS 14 The updated results of the 12 C+Pb experiments carried out with LNL ED

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS 15 Experimental approaches to the separation and detection of ERs Dubna experiments on synthesis of SHE with DGFRS

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS 16 Experimental approaches to the separation and detection of ERs Results of Dubna DGFRS experiments on synthesis SHE with Z=113, 115,and 117 Yu.Ts. Oganessian et al., PRC 87, (2013); PRC 87, (2013)

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS 17 Dubna DGFRS experiments on synthesis SHE 19 nuclei synthesized 53 nuclei identified in their decays

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS 18 Acknowledgements Dubna DGFRS experiments on synthesis SHE Yu.Ts. Oganessian 1, F.Sh. Abdullin 1, C. Alexander 2, J. Binder 2, R. A. Boll 2, S.N. Dmitriev 1, J. Ezold 2, K. Felker 2, J.M. Gostic 3, R.K. Grzywacz 2,4, J.H. Hamilton 5, R.A. Henderson 3, M.G. Itkis 1, K.Miernik 2, D. Miller 4, K.J. Moody 3, A.N. Polyakov 1, A.V. Ramayya 5, J.B. Roberto 2, M.A. Ryabinin 6, K.P. Rykaczewski 2, D.A. Shaughnessy 3, I.V. Shirokovsky 1, M.V. Shumeiko 1, M.A. Stoyer 3, N.J. Stoyer 3, V.G. Subbotin 1, A.M. Sukhov 1, Yu.S. Tsyganov 1, V.K. Utyonkov 1, A.A. Voinov 1, and G.K. Vostokin 1 1 Flerov Laboratory of Nuclear Reactions JINR, RU Dubna, Russian Federation 2 Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA 3 Lawrence Livermore National Laboratory, Livermore, California 94551, USA 4 Dep. of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA 5 Dep. of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA 6 Research Institute of Atomic Reactors, RU Dimitrovgrad, Russian Federation LNL experiments on study of ER production in various reactions N.A. Kondratiev 1, L. Corradi 2, E. Fioretto 2, T. Mijatović 2, R. Silvestri 2, A.M. Stefanini 2, P. Mason 3, G. Montagnoli 3, and F. Scarlassara 3, 1 Flerov Laboratory of Nuclear Reactions JINR, RU Dubna, Russian Federation 2 INFN, Laboratori Nazionali di Legnaro, I Legnaro (Padova), Italy 3 INFN and Dipartimento di Fisica, Università di Padova, I Padova, Italy

14th INTERNATIONAL CONFERENCE ON NUCLEAR REACTION MECHANISMS 19 Thank you for your attention