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106 th Session of the JINR Scientific Council September 24-25, 2009, Dubna

Perspectives of JINR – ORNL Collaboration in the Studies of Superheavy Elements For JINR: Yu.Oganessian. 106 th Session of the JINR Scientific Council September 24-25, 2009, Dubna. CONTENT. Short Introduction The “Island of Stability” of SHE

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106 th Session of the JINR Scientific Council September 24-25, 2009, Dubna

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  1. Perspectives of JINR – ORNL Collaboration in the Studies of Superheavy Elements For JINR: Yu.Oganessian 106th Session of the JINR Scientific Council September 24-25, 2009, Dubna

  2. CONTENT • Short Introduction • The “Island of Stability” of SHE • Test of nuclear models • Beyond the Periodic Table • Setting of the Z=117-experiment • Our efforts

  3. Act+ 48Ca from 2000 cold fusion about 25 years Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  4. Experimental technique Gas-Filled Recoil Separator Transmission for: EVR 35-40% target-like 10-4-10-7 projectile-like 1015-1017 Registration efficiency: for α-particles 87% for SF single fragment 100% two fragments ≈ 40% Beam: 48Ca Targets: Isotopes of U, Pu, Am, Cm and Cf(now Bk)

  5. producer Isotope enrichment (%) 233U IAR 99.97 238U — 99.3 237Np IAR 99.3 242Pu IAR 99.98 244Pu ORNL 98.6 243Am IAR / ORNL 99.9 245Cm IAR 98.7 248Cm ORNL/ IAR 97.4 249Bk ORNL ≥ 95 249Cf ORNL / IAR 97.3 Target materials Reactions of Synthesis Reactions of Synthesis Act. + 48Ca Projectiles 48Caproduced by Heavy Ion Accelerator U - 400 Energy: 235-250 MeV Intensity: 1.0-1.5 pμA Consumption: 0.5-0.8 mg/h Beam dose: (0.3-3.0)∙1019

  6. 226Ra Decay chains Decay chains 237Np 243Am 242Pu, 245Cm 117/293 117/294 244Pu, 248Cm 249Cf 115/289 115/290 2009-2010 113/285 113/286 249Bk +48Ca 111/282 111/281 T1/2= 320d Collaboration: FLNR (Dubna) ORNL (Oak-Ridge) LLNL (Livermore) IAR (Dmitrovgrad) Vanderbilt University (Nashville) 34 nuclides 109/277 109/278 Hs/270 σ4n≈10pb 10 s a 9.06 107/274 107/273 Sg/266 0.2 s 105/270 105/269 104/269 104/270 103/266 102/266 164 48Ca +

  7. Decay Properties of SH- nuclei

  8. Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

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

  10. Act. + 48Ca Half lives of nuclei with Z ≥ 110 Half lives N=162

  11. With Z >40% larger than that of Bi, the heaviest stable element, that is an impressive extension in nuclear survival. Although the SHN are at the limits of Coulomb stability, shell stabilization lowers: the ground-state energy, creates a fission barrier, and thereby enables the SHN to exist. The fundamentals of the modern theory concerning the mass limits of nuclear matter have been verified experimentally for the first time Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  12. Test of nuclear models Test of nuclear models Element 120

  13. Microscopic theory and the properties of heaviest nuclei Microscopic theory and the properties of heaviest nuclei RMF HFB MMM

  14. 298,299120EVR 3μs 116(exp) 0.03s Z=116 Z=120 Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  15. 3n 251Cf (α/898y) 238U + 64Ni GSI 2008 244Pu + 58Fe FLNR 2007 248Cm +54Cr GSI 2010 252Cf + 50Ti (α,SF/2.6y)

  16. Cold fusion cross sections and fusion probability Cold fusion cross sections and fusion probability Z=112-118 Z=112-118 249Bk+48Ca Act.+48Ca 251Cf+50Ti 248Cm+54Cr 244Pu+58Fe 238U+64Ni Ex=12-15 MeV Cold fusion ~ 0.05-0.1pb 1 event / year SHE Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  17. Beyond the Periodic Table

  18. relativistic relativistic Chemical properties Chemical properties Ca 20 86 Pu 94 n o i t a l o s i l a c i m e h C 14 12 Cd 4 8 Hg Rn 80

  19. Element 112 is a noble metal – like Hg room temperature Compound Hg(Au) and 112(Au) Compound Hg(Au) and 112(Au) R. Eichler et al., Nature 447 (2007) 72 Reaction: 242Pu(48Ca,3n)287114[0.5s]→α→283112[3.6s] Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  20. critical 112 114 SHE Atomic properties Atomic properties Hg Pb

  21. 249Bk(320d) + 48Ca 243Am(7370y) + 48Ca more and more inert? Periodic Table of Elements Periodic Table of Elements Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  22. 243Am + 48Ca σ =4.2pb 243Am + 48Ca σ =0.03pb 209Bi + 70Zn 237Np + 48Ca half-life 0.24 ms 0.07s 0.5s 10s JINR (Dubna) - - LLNL (Livermore) - - ORNL (Oak-Ridge) collaboration RIKEN (Tokyo) Isotopes of Element 113 Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  23. GAS CATCHER GAS CATCHER Δt = 20-50 ms transmission ≈ 50% rotating target H2+B separating window beam RECOILS q=qeq entrance window RF pumping q=1+He beam RF stopping volume RF+E E acceleration beam of high quality pumping Guy Savard from Argonne National Laboratory

  24. Mass Analyzer of Super Heavy Atoms (MASHA) Mass measurements Transmission for Hg-atoms ≈ 75% gas catcher intermediate focus Position of the detector array magnetic electrostatic deflection deflection D M/M 3500

  25. 3ms 1ms 118 119 254Es + 48Ca 251Cf + 48Ca Periodic Table of Elements Periodic Table of Elements

  26. Setting an Experiment on the Synthesis of Setting an Experiment on the Synthesis of Element 117

  27. high neutron flux high intensity of 48Ca beam (~1.5 pμA) HIFR, ORNL U- 400FLNR, JINR chemical separation from 252Cf (factor 1011) 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 Reaction: 249Bk + 48Ca → 297117* →294-293117 + 3-4n T1/2=320d Yu.Oganessian. Perspectives of JINR – ORNL Collaboration in the studies of SHE. JINR Scientific Council, Sept 24-25. 2009, Dubna

  28. 22 mg of 249Bkhave been produced with neutrons of HIFR ORNL

  29. 274 107 8.42 MeV 269 270 5.1min 105 7.94 MeV 7.71 MeV 0.7h 4.8h 265 266 103 103 266 102 6.41 MeV 6.55 MeV 27y 5.9y SF Expected decay chain of the isotopes of element 117 A. Sobiczewski10/24.03.09

  30. 249Bk + 48Ca 117 Cross sections

  31. Gain factors for production of Super-heavy nuclei

  32. In order to understand the limits in the existence of the elements we had to move: All these tasks took us about 40 years Now we would like to have it in 6 years!

  33. Thanks for your attention

  34. Cross sections 117

  35. Exp.2007 Tads of Hg and Element 112 on Quartz and Gold Predictions V. Pershina 2006 Quartz Mobile adsorption (quartz): Tads 100 0 100 C Hg 112rel112nrRn Localized adsorption (gold): Gold Tads 100 0 100 C

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