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107th Session of the JINR SCIENTIFIC COUNCIL 18–19 February 2010 , Dubna

Status of the experiments on the synthesis of Element 117. Yuri Oganessian FLNR (JINR). for collaboration. 107th Session of the JINR SCIENTIFIC COUNCIL 18–19 February 2010 , Dubna. Collaboration. Yu. Oganessian 2010. FLNR, JINR (Dubna)

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107th Session of the JINR SCIENTIFIC COUNCIL 18–19 February 2010 , Dubna

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  1. Status of the experiments on the synthesis of Element 117 Yuri Oganessian FLNR (JINR) for collaboration 107th Session of the JINR SCIENTIFIC COUNCIL 18–19 February 2010, Dubna

  2. Collaboration Yu. Oganessian 2010 FLNR, JINR (Dubna) ORNL (Oak-Ridge, USA) LLNL (Livermore, USA) IAR (Dimitrovgrad, Russia) Vanderbilt University (Nashville, USA)

  3. 3-4n α1 249Bk +48Ca α2 α3 α4 α5 α6 α7 RAPID COMMUNICATIONS 3-4n PHYSICAL REVIEW C 69, 021601(R) (2004) Experiments on the synthesis of element 115 in the reaction 243Am(48Ca, xn)291−x115 243Am + 48Ca Yu. Ts. Oganessian et al., Yu. Oganessian 2010 Yu.O. “SHE”, at the Colloquium, ORNL, 02/10/05

  4. Symposium “Prof. Joseph Hamilton: 50-year career at Vanderbilt University”. October 2-3, 2008, Nashville, USA Yu. Oganessian 2010

  5. Scientific Collaboration and Material Transfer Agreement № 500-09-01 between the UT-Battelle, LLC, the Management and Operating Contractor for Oak-Ridge National Laboratory, Oak Ridge, TN, USA and the Flerov Laboratory of Nuclear ReactionsJoint Institute for Nuclear ResearchDubna, Russia Yu. Oganessian 2010 The material produced by ORNL will be used for carrying out a joint experiment on the synthesis of new super-heavy chemical element Z=117 of the Periodic System of Elements for studying the features of this element and its radioactive decay products and for studying the formation of super-heavy nuclei in heavy-ion reactions. UT-BATTELLE, LLC JINR Name: K.P. Rykaczewski Name: Yu.Ts. Oganessian Spectroscopy task leader Scientific leader of FLNR Deputy Director J.R. Roberto Director A.N. Sissakian March 02, 2009 March 12, 2009

  6. Yu. Oganessian 2010 Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  7. 249Bk (320d) Z.H. Liu and Jing-Dong Bao. Phys. Rev., C80, 034601 (2009) Yu. Oganessian 2010 Cross sections (pb) 3n 4n Compound nucleus mass number Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  8. high intensity of 48Ca beam (~1.5 pμA) beam dose ≥3·1019 high neutron flux HIFR, ORNL 4.5·1019 U- 400FLNR, JINR chemical separation from 252Cf (factor >108) 3·108 Separation, Detection & Identification 1 SH-atom / 1012 reaction products target preparation 36cm2 0.25 μm BkO2+ 1.6 μmTi DGFRS Dubna Gas-filled Recoil Separator IAR, Dimitrovgrad 1event|Z=117→ 0.14pb Reaction: 249Bk + 48Ca → 297117*→294-293117 + 3-4n Yu. Oganessian 2010 T1/2=320d

  9. The Bk-249 was produced at ORNL (USA) by irradiation: of Cm and Am targets for approximately 250 days by thermal-neutron flux of 2.5  1015neutrons/cm²·s in the HFIR (High Flux Isotope Reactor).  Yu. Oganessian 2010 Irradiation ends December 2008 Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  10. Yu. Oganessian 2010 50 Ci 50 Ci The purified product contained 22.2 mg of Bk-249, approximately 1.7 ng of Cf-252, and no otherdetectable impurities. Chemical isolation of the Bk-fraction May 2009 Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  11. Target Target 310 μg/cm2 BkO2 on 1.5 μm-Ti foil ω = 1700 rpm 6 cm2 Yu. Oganessian 2010 600 120 mm target-making June 2009

  12. Dubna Gas-Filled Recoil Separator Dubna Gas-Filled Recoil Separator Experimental technique Yu. Oganessian 2010 Transmission for: EVR 35-40% target-like 10-4-10-7 projectile-like 10-15-10-17 Registration efficiency: for α-particles 87% for SF single fragment 100% two fragments ≈ 40% beam 48Ca target 249Bk Experiment was started July 27

  13. Yu. Oganessian 2010 First run: from July 27 to October 23, 2009 Beam dose: 2.4·1019

  14. a 1 a 2 48Ca a 7–15 MeV y0 3 9.96 MeV 293 22.04 mm 117 10.7–11.4 MeV ≤ 132 ms Δy=y1-y0 ≤ 2.2 mm 10.25 MeV 0.51s 22.20mm 9.79 MeV 0.24 s 10.91 MeV 22.09mm 53.01 ms 22.16 mm 189.4 MeV 31.66 s 22.01mm the beam was switched off SF low-background detection scheme 249Bk target focal plane detector array Yu. Oganessian 2010 separator 4m Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  15. 117 Spectra of fission-like signals α1 beam-on beam-on 1680 h 1680 h SF 115 113 α2 α3 111 252,254Cf beam-off 80 h 80 h 10-3/s 7·10-5/s 1.5·10-7/s 2·10-6/s per strip / position Yu. Oganessian 2010 Spectra of the α-like signals 211Po 214Po 213Po 212Po (α+e-) (α+e-) 212Po beam-off

  16. Cross sections Cross sections 293 294 ACN=297 Yu. Oganessian 2010 249Bk + 48Ca Cross sections (pb) Calc. 4n Y. Abe et al., Int. J. Mod. Phys. 17 (2008) 2214 V.I. Zagrebaev & W Greiner Phys. Rev. C78, 034610 (2008) 3n Z.H. Liu & Jing-Dong Bao Phys. Rev. C80, 034601 (2009) Excitation energy of the 297117* (MeV) Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  17. Ex=39 MeV (48Ca,4n) Ex=35 MeV (48Ca,3n)

  18. 3n 4n

  19. 249Bk +48Ca T1/2= 320d • Collaboration: • FLNR (Dubna) – ORNL (Oak-Ridge) – • LLNL (Livermore) – IAR (Dmitrovgrad) • Vanderbilt University (Nashville) Decay chains Decay chains 48 nuclides Yu. Oganessian 2010

  20. Spontaneous fission half-lives Spontaneous fission half-lives Actinides Trans-actinides Superheavy nuclei

  21. “critical” zones P. Moller et al., Phys. Rev., C79, 064304 (2009) α-decay Spontaneous fission Yu. Oganessian 2010 ▼ Z=117 ▼ ▼ ▼ ▼ ▼ Z=112 ▼

  22. Theory & Experiment Theory & Experiment red – 249Bk. + 48Ca 5% 117 blue – cold fusion black – Act. + 48Ca Yu. Oganessian 2010 PRELIMINARY deformed spherical

  23. blue – cold fusion black – Act.+48Ca red – 249Bk+48Ca PRELIMINARY Yu. Oganessian 2010 Alpha decay energy Half-lives Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  24. Cross sections Cross sections 208Pb+48Ca Ex≈ 40 MeV Yu. Oganessian 2010 226Ra+48Ca 249Bk+48Ca

  25. Experiment is still going on…

  26. Subsequent research Chemistry of Element 113

  27. 249Bk(320d) + 48Ca 243Am(7370y) + 48Ca more and more inert? Periodic Table of Elements Periodic Table of Elements Yu. Oganessian 2010 Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  28. 249Bk + 48Ca σ =1.3pb σ =4.2pb 243Am + 48Ca σ =0.03pb 209Bi + 70Zn 237Np + 48Ca T1/2 0.24 ms 0.07s 0.5s 5.5s JINR (Dubna) - - LLNL (Livermore) - - ORNL (Oak-Ridge) collaboration RIKEN (Tokyo) Isotopes of Element 113 Yu. Oganessian 2010 Yu. Oganessian. “Status of the experiment on the synthesis Z=117”. JINR SC, Feb.18-19, 2010, Dubna

  29. Adsorption enthalpy of elements 112 through 115 (in kJ/mol) Red– experiment: a) Soverna, PSI Report 2004, p. 8; b) A. Yakushev, et al. c) S. Soverna et al. Radiochim. Acta, 93, 1-5 (2005). d) S. König, et al. PSI Annual Report 2007? e) F. Haennsler, et al PSI Annual Report 2004, p. 9. f) -207 21 (Haenssler); -222  8 (Fan); 242 on the picture; F. Haenssler et al., PSI AR, 2005, p. 3. g) R. Eichler et al. Angew. Chem. Int. Ed. 47, 1-6 (2008). h) R. Eichler and M. Schädel, J. Phys. Chem. B 106, 5413-20 (2002). k) R. Eichler, private commun. Black- calculations. Blue – estimates from the calculations for the dimer with respect to the exp. for the homolog. Green ? – with respect to the exp. for Rn based on the calculations Yu. Oganessian 2010

  30. Reaction: 249Bk(48Ca,4n)293117→α→293115 →α→289113[5.5s] →α→ 283Rg[26s] Yu. Oganessian 2010 Au SiO2

  31. Thanks for your attention

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