Yuri Oganessian Flerov Laboratory of Nuclear Reactions Joint Institute for Nuclear Research SHE in JINR 109 th Session of the JINR Scientific Council Feb.17-18, 2010, Dubna.

Synthesis of SHE with 48 Ca-induced reactions 10 years

Decay chains Decay chains Pu, 248 Cm + 48 Ca Z= Talk at the Meeting of RAS, Nov., μs 0.7 ms s 0.5 min 2.5 s 0.06 s

A/ZSetupLaboratoryPublications SHIPGSI DarmstadtEur. Phys. A32, 251 (2007) COLDPSI-FLNR (JINR)NATURE 447, 72 (2007) 286, BGSLRNL (Berkeley)P.R. Lett. 103, (2009) 288, , TASCA SHIP GSI – Mainz GSI Darmstadt P.R. Lett. 104, (2010) Eur. Phys. (to be published) Confirmations Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

new superheavy elements 48 new isotopes Yu. Oganessian T 1/2 = 320d 249 Bk + 48 Ca 117 Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

Cold fusion 100 Total evaporation residues cross sections (pb) Atomic number Cross sections 48 Ca-induced reactions SHE factor ~300

Technical Achievements & Collaborations

“in flight” separation chemical separation 1985 GSI, Darmstadt, Germany * LBL, UC Berkeley, CA Univ. of Mainz, Germany LANL, Los Alamos, NM EIR, Würenlingen, Switzerland Search for Element 116 in 248 Cm + 48 Ca reaction FLNR, Dubna LLNL, Livermore, CA

The neutron-rich isotopes of the Actinides was produced at ORNL (USA) by irradiation: of Cm and Am targets in each campaine for approximately 250 days by thermal-neutron flux of 2.5  n/cm ² ·s in the HFIR (High Flux Isotope Reactor). TARGETS Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

Beam dose: 2.4· % BEAMS

Dubna Gas-Filled Recoil Separator From the characteristics of the DGFRS, it follows that with a 48 Са-beam dos e of 3∙10 17 realized for 1 day the observation of one decay event corresponds to the production cross section of about 10 pb. beam 48 Ca target DETECTORS

Decay Properties of SHE: expected & obtained

Alpha-decay

Trans-actinides Superheavy nuclei Spontaneous fission half-lives Actinides 48 Ca-induced reactions

With Z >40% larger than that of Bi, the heaviest stable element, we see an impressive extension in nuclear survival. Although SHN are at the limits of Coulomb stability, shell stabilization lowers ground-state energy, creates a fission barrier, and thereby enables SHN to exist.. The fundamentals of the modern theory concerning the mass limits of nuclear matter have obtained experimental verification Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

Consequences

neutrons → protons → Nuclear structure and decay properties of the SHN Nuclear Physics Chemical properties of the SHE Chemistry Search for new shells Nuclear theory Search for SHE in Nature Astrophysics Electronic structure of SHE-atoms Atomic Physics Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

Decays & Spectroscopy of Super heavy Nuclei

new superheavy elements new isotopes Previously known nuclei from cold Fusion reactions It is questionable that “filling in empty spaces” would give us significant information about nuclear structure of SHE neutrons protons

σ xn ~ ( Γ n / Γ f ) x ; х – number of evaporated neutrons ( Γ n / Γ f ) ~ exp ( B f – B n ) / T B f = B f LD + ΔE Shell 0 Cross sections Hot fusion E x =45-50 MeV SHN

Z= N= T SF = s Z= very neutron-rich nuclei N= T 1/2 = s Spontaneous fission of heavy and super heavy elements

Yield (rel. units) rel. units E. K. Hulet, et al., P.R. C40, 770 (1989) Q F = 268 MeV Z 1 ≈ Z 2 = N 1 = N 2 = 82

Act Ca N=162 “on line” “gas catcher” Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

beam 48 Ca target ε =0.5 mm·mrad ΔE=0.5 eV Experimental l technique FLNR / ANL

Superheavy Atoms Chemistry of the SHE

(point charge) Z max =1/ α=137 where α is fine-structure constant Heaviest atoms in QED SHE Hg (finite size) Z max ≈173

Z max r max - principal maximum of the wave function of the outermost orbital

chemical compound (Au·Hg) (Au·112 ) R. Eichler et al., Nature 447 (2007) 72 FLNR / PSI

Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna SHE ion charge exchange in the gas-target Beam of SHE with variable energy

Theoretical Models Nuclear forces Macro – Microscopic Model (MMM) Hartry – Fock – Bogolubov (HFB) Relativistic Mean Field (RMF)

MMM HFB + 48 Ca 251 Cf + 50 Ti Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

Strategy

Gain factors for production of Super-heavy nuclei Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna Current experiments 2.5pμA

Dear Yuri We have received authorization from DOE for production of Bk-249 for the upcoming experiments at Dubna and at GSI. Your letter and your trip to DOE were very helpful in securing approval. Thank you for your support. We anticipate that the material will be ready for shipment later this year in the December-January timeframe. A more detailed schedule will be forthcoming. We look forward to working with you on these exciting experiments. With best regards, Jim Feb.17, 2011, 1:59 AM. From ORNL, USA

Thank you

New basisType / parameters New multi-charge ion sources or its combinationsPIG-type / ECR-type New accelerator with high beam intensity and projectile energy ≤ 10 MeV·A pμA of 48 Ca-ions (beam power ~5 kW) New experimental hall2500 m 2 New separation setups, fast transport systems and sophisticated detector arrays Thick target + Gas-Field Separator + Gas Catcher New production of 248 Cm, 249 Bk, 251 Cf. Development of the target technologies and constructions of new target station Programs for HIFR and RIAR (Dimitrovgrad) Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

TaskThe state of things Completion of the synthesis of SHE Z= (now Z= ) IUPAC approval and giving the names to SHE Upgrade of U-400 cyclotron pμA of 48 Ca and 50 Ti beams (ready / on demand) Gas-catcher transport system (collaboration with ANL and Cycl. Inst. of the Texas A&M University) transport time ≥ 5ms, transmission ≥ 50% (production began) Separation of 251 Cf and 247 Cm-isotopes. Target preparation New separator. (find solution: possibly new separator at ORNL) Synthesis of element Z=118reaction 251 Cf( 48 Ca,3-4n) 296, Synthesis of element Z=120 New detectors: X-rays and γ-rays to study of SHE and fast detector for synthesis Z=118, 120 as well as charge particles to study α-decay & SF reaction 251 Cf+ 50 Ti, (production of 50 Ti-beam at U400 cyclotron) Under construction in ORNL and JINR

P. Moller et al., Phys. Rev., C79, (2009) spherical deformed ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ Z=117 Z=112 ▼ ▼ ▼ ~8pb ≤0.6pb Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

more and more inert? Periodic Table of Elements Yu. Oganessian. Colloquium at MIT, Feb.10, 2011

243 Am, 249 Bk 237 Np, From reactions: 48 Ca + N= Z=104SF

M. Bender et al., PRC60 & PLB Cf + 48 Ca → 296 (118) +3n → Z=114 / N= Cf + 50 Ti → 298 (120) +3n → Yu. Oganessian “SHE in JINR” 109-th Session of the SC of JINR, Feb , 2011, Dubna

Oganessian, ENAM (2008) Neutron number Proton number Island of Stability Stability Shoal Peninsula Continent Sea of Instability 1µs 1s1h 1y 1My Opportunities for future research New targets New beams New elements New isotopes Higher neutron numbers New physics New chemistry