Production of Super Heavy Nuclei at FLNR. Present status and future

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ECOS 2012,Loveno di Menaggio, 18-21 June 2012 Production of Super Heavy Nuclei at FLNR.

1 ECOS 2012,Loveno di Menaggio, June 2012 Production of Super Heavy Nuclei at FLNR. Present status and future M. ITKIS Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research

2 BASIC DIRECTIONS of RESEARCH 1. Heavy and superheavy nuclei: synthesis and study of properties of superheavy elements; chemistry of new elements; fusion-fission and multi-nucleon transfer reactions; nuclear-, mass-, & laser-spectrometry of SH nuclei. 2. Light exotic nuclei: properties and structure of light exotic nuclei; reactions with exotic nuclei. 3. Radiation effects and physical groundworks of nanotechnology

JINR s advantages Unique beams of heavy ions: 48 Са - 58 Fe, 6 He, 8 He Beam on target time up to 12,000 hours/year Unique actinide targets 237 Np 249 Cf Cryogenic D-T- target Advanced

3 JINR s advantages Unique beams of heavy ions: 48 Са - 58 Fe, 6 He, 8 He Beam on target time up to 12,000 hours/year Unique actinide targets 237 Np 249 Cf Cryogenic D-T- target Advanced experimental set-ups Highly-qualified scientists and engineers Broad international cooperation: JINR Member States, Germany, the USA, Finland, France, Italy, Japan, Switzerland, etc. M. Itkis 3

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

5 Decay chains 244 Pu, 248 Cm + 48 Ca Z= s s ms min 170 μs s

6 Confirmations A/Z Setup Laboratory Publications SHIP GSI Darmstadt Eur. Phys. J. A32, 251 (2007) COLD PSI-FLNR (JINR) NATURE 447, 72 (2007) 286, BGS LRNL (Berkeley) P.R. Lett. 103, (2009) 288, TASCA GSI Mainz P.R. Lett. 104, (2010) 292, SHIP GSI Darmstadt Eur. Phys. J. A48, 62 (2012)

7 Press Release Press Release :27 Element 114 is Named Flerovium and Element 116 is Named Livermorium Priority for the discovery of these elements was assigned to the collaboration between the Joint Institute for Nuclear Research (Dubna, Russia) and the Lawrence Livermore National Laboratory (Livermore, California, USA). The name flerovium will honor the Flerov Laboratory of Nuclear Reactions where superheavy elements are synthesised. Georgiy N. Flerov ( ) was a renowned physicist, author of the discovery of the spontaneous fission of uranium, pioneer in heavy-ion physics, and founder in the Joint Institute for Nuclear Research the Laboratory of Nuclear Reactions (1957). The name livermorium honors the Lawrence Livermore National Laboratory. A group of researchers of this Laboratory with the heavy element research group of the Flerov Laboratory of Nuclear Reactions took part in the work carried out in Dubna on the synthesis of superheavy elements including element 116.

8 Cn 287 Fl β-stability 291 Lv Island of stability of SHE

9 6 new heaviest elements new isotopes

10 No Cold fusion No 48Ca-induced reactions Hs Hs K. Siwek - Wilczynska et al. (2011) Coulomb repulsion Coulomb repulsion M. Kowal et al. (2010)

11 Total evaporation residues cross sections (pb) Cold fusion factor 500 Cross sections SHE Atomic number 48 Ca-induced reactions

12 Current experiments The conformation of previous results for Z = 113, 115, 117 and 118

13 243 Am( 48 Ca,2n) 117 Cross bombardment CN Cross section (pb) Excitation energy (MeV)

14 249 Bk( 48 Ca,4n)

15 In solution Berkelium -249 at hot cell Feb. 5, 2012 ORNL, Oak Ridge, Tennessee, USA

18 Synthesis of new isotope of Element 118 α CN α α α with heaviest target 251 Cf from ORNL (USA) Approved by IUPAC

Target preparation for synthesis of the new Isotope of the Element 118 251 Cf nuclide production paths

(n,f) Cf250 α Cf251 251 α, (n,f) Cf252 α, SF Cf253 β -, (n,f) Cf254 α, SF 97 Bk Bk249 β - Bk250 β -

β - Cm250 α, β -,SF 95 Am Am241 α Am242 β -,EC,(n,f) Am243 α Am244 β - Am245 Am246 Collaboration: β -

19 Target preparation for synthesis of the new Isotope of the Element Cf nuclide production paths 100 ORNL Fm Es Fm254 α Es253 α Fm255 α Es254 α, β -,EC Fm256 SF Es255 β - Fm257 α, (n,f) Cf Cf249 α, (n,f) Cf250 α Cf α, (n,f) Cf252 α, SF Cf253 β -, (n,f) Cf254 α, SF 97 Bk Bk249 β - Bk250 β - Bk251 β - 96 Cm Cm242 α Cm243 α, (n,f) Cm244 α Cm245 α, (n,f) Cm246 α Cm247 α, (n,f) Cm248 α, SF Cm249 β - Cm250 α, β -,SF 95 Am Am241 α Am242 β -,EC,(n,f) Am243 α Am244 β - Am245 Am246 Collaboration: β - β - 94 Pu Pu240 α Pu241 β -, (n,f) Pu242 α Pu243 β - Pu244 α Pu245 β - Pu246 FLNR / ORNL / Vanderbilt UNI β -

20 What is beyond 118 element? The search for new ways to SHE

The formation of 294116 in the reactions with

21 The formation of in the reactions with 48Ca and 50Ti-ions Two-dimensional TKE/M matrixes and mass yields for the reactions 48Ca+246Cm and 50Ti+244Pu at the excitation energies E*=32-50 MeV

22 Capture cross sections for the reactions 50 Ti+ 244 Pu and 48 Ca+ 246 Cm

23 Z t Z p TKE (MeV) E * CN 45MeV Mass (u) Yield (arb. units) Ca+ 238 U 286 Cn Y(A CN /2 20)=12% 58 Fe+ 244 Pu Y(A CN /2 20)=8% 22 u 64 Ni+ 238 U Mass (u) Counts Y(A CN /2 20)=4% 11 u 34 u Viola Systematics 70% σer= 1pb % σer < 30 fb % σer < 3 fb TKE (MeV) for A CN /2 20

24 Beyond 48 Ca: 50 Ti and 54 Cr induced fusion reactions Probably these elements are the last ones which will be synthesized in the nearest future

25 Normal Asymmetric QF Reverse Ca Cm U Cm Yield (arb. unit) QF QF+CNF Mass (u) X3 Z=28 N=50 N=126 Z=50 N=82 Z= Driving potemtial (MeV) Mass (u) N=126 Z=82 Z 106 Driving potential is calculated near the scission point in nrv.jinr.ru (proximity model) 25

Asymmetric QF Reverse Xe Cm U Cm Driving potential (MeV) 500 480 460 440 420 N=50 80 100 120 140 160 180 200 220 240 260 280 300 Mass (u) nrv.

26 Asymmetric QF Reverse Xe Cm U Cm Driving potential (MeV) N= Mass (u) nrv.jinr.ru (proximity model) Z=114 N= Mass (u) N=126 Z=82 Z

27 Superasymmetric fission of superheavy nuclei W. Greiner (International Workshop on Fusion Dynamics at the Extremes, 25-27May 2000) Superasymmetric fission of nuclei with A~200 u 27 M.G. Itkis, Perspectives in Nuclear fission Tokai, Japan, March 2012

28 12 C+ 248 Cm 260 No Cm( 12 C, f) FLNR experiment Yield (%) Fm(n th, f) W.Greiner theory M L /M H = 52/ Mass (u)

29 136 Xe+ 248 Cm???? 238 U+ 248 Cm 29

30 protons Electronic structure of SHE-atoms Atomic Physics Chemical properties of the SHE Search for new shells Nuclear theory 120 Chemistry Nuclear structure and decay properties of the SHN SHE Nuclear Physics Search for SHE in Nature Astrophysics U Th Pb Bi neutrons 190

31 SHE in Dubna and after

32 I would like to stop here and make a short conclusion: we have received an evidence that superheavy elements exist moreover we know how to produce them we know also roughly their decay properties All this allows us to consider different approaches to study the detailed properties of SHE

33 However, we produce them in very small quantities, much less than could be reached with modern experimental technique So I shall talk more about these opportunities and on our plans for the near and distant future.

Production Increase a beam dose today: 4.5 10 19 with factory: 1.

34 Production Increase a beam dose today: with factory: factor: 30 it requires to Increase: beam intensity and beam time New accelerator beam intensity up to pµa SHE-Factory ~ 7000 h/year a limit of the beam intensity is defined entirely by target resistance and available amount of target 5 8 material МeV A new laboratory

35 ACCELERATORS Projectiles Beam parameters HI-Physics U-400R Stable and RIB (T 1/2 > 0.1s) SHE-Factory DC-280 Stable only Projectile masses 4He 238U 40Ar 86Kr Energy range МeV/n 5 8 МeV/n Energy resolution 0.5% 1.5% Beam intensity (for 48Са) 2.5 pμa pμa SHE-research program 30% ~100% Registered decay chains of SHN 120 (now 30) (per year) State of readiness 75% In course of

36 Gain factors for the production of Superheavy nuclei Current experiments Z=113, 115, 117 and pμA U-400 & DGFRS Z=117 1 Upgrade of U p A 2.5 Experimental hall independent work New type experimental facilities SC separator + Gas catcher New Accelerator p A 15

37 FLNR backside in January 2012

38 April 16, 2012 SHE factory SHE factory

39 Schedule for SHE-Factory Feb Building works Equipment assembling 30 months 18 months 42 months Equipment completion 54 month

40 Schedule for U400R Current experiments Jan months spadework Upgrade U400 U400R 25 months 13 months 12 months Building works 18 months 43 months

41 FLNR (JINR) 2016 SHE Factory 1000m 2 Nuclear physics with stable & RI-beams 1500m 2 DRIBs U200 IC100 Production & studies of the exotic nuclei Applied research Nano/Lab 1500m 2 DC-280 new U400R upgraded MT25 U400M &SC ECR U400M-U400R Accelerator Complex

Conclusion While the relative contribution of QF to the capture cross section mainly depends on the reaction entrance channel properties, the features of asymmetric QF are determined essentially by

42 Conclusion While the relative contribution of QF to the capture cross section mainly depends on the reaction entrance channel properties, the features of asymmetric QF are determined essentially by the driving potential of a composite system. The fragment yield increases when the both formed fragments are close to nuclear shells as in the case of QF (asymmetric QF), as well as in the case of fusion-fission (bimodal fission, asymmetric fission, superasymmetric fission). At the transition from Ca to Ni projectiles the contribution of QF process rises sharply and Ni ions is not suitable for the synthesis of element Z=120 in the complete fusion reactions. An alternative way for further progress in SHE can be achieved using the deep-inelastic or QF reactions. To estimate the formation probabilities of SHE in these reactions the additional investigations are needed.

capture touching point M.G. Itkis, Perspectives in Nuclear fission Tokai, Japan, March

capture touching point M.G. Itkis, Perspectives in Nuclear fission Tokai, Japan, March Nuclear Reaction Mechanism Induced by Heavy Ions MG M.G. Itkis Joint Institute for Nuclear Research, Dubna 5 th ASCR International Workshop Perspectives in Nuclear fission Tokai, Japan, 14 16 16March 212