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Discovery of the Island of Stability for Super Heavy Elements The Eighth International Particle Accelerator Conference Discovery of the Island of Stability for Super Heavy Elements Yuri OGANESSIAN Flerov Laboratory of Nuclear Reactions Joint Institute for Nuclear Research IPAC’17 May19, 2017. Copenhagen, Denmark Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark For more than 22 centuries From Democritus (460 - 371 BC...) to Dalton (1766 - 1844) it was assumed that the objects around us are made up of tiny indivisible particles - atoms interacting with each other. In 1808 36 elements were known only 63 elements were already know by that time Dmitri Mendeleev 1869 Genuine D.I.Mendeleev’s Table Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark 86 elements were already known by that time electrons Z nucleus Ernest Rutherford March7, 1911 Planetary model of atom Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark In attempts to describe the properties of nuclear matter, George Gamow made a daring assumption that atomic nucleus may be similar to a drop of positively charged liquid. George Gamow 1928 In fact, the density of nuclear liquid is 1015 times more than that of water Charged Liquid Drop Model of the atomic nucleus. G. Gamow, 1928. Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark We will be discussing today the problem of synthesis and properties of extremely heavy nuclei to get answers to questions about: • How big the nuclei can be? • What of proton and neutron number they may have? • Where is the mass limit of the nuclei? • How many chemical elements can be and what are their properties? Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Nuclear fission 10 N. Bohr J.A. Wheeler 1939 Z=92U 5 G.N. Flerov Bf=6 MeV 0 16 tential(MeV) energy 10 years (exp.) o P 1940 Nuclear deformation K.A. Petrzhak Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Nuclear fission 10 N. Bohr J.A. Wheeler 1939 Z=92U 5 G.N. Flerov Bf=6 MeV 0 16 tential(MeV) energy 10 years (exp.) o P B =0 1940 10-19 s f Nuclear deformation Z≥100 K.A. Petrzhak Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark ChartChart ofof nuclidesnuclides Macroscopic theory (Liquid Drop Model) about 50 years ago… 120 T = 2·10-7 y ber SF m 110 The nuclei are unstable 102No / Tα ≈ 2 s with respect to spontaneous fission 100 proton nu proton Th 90 Bi 9 92U / Tα = 4.5·10 y T = 1016 y 80 SF 82Pb / stable 70 110120130140150160170 180 190 neutron number Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Th U neutron capture Pu HI-fusion 20 Cm Cf Fm 10 /s 102 SF T g o 104 L 0 LD -10 -14 10 s -20 0.80 0.85 0.90 22 Fissility x = (Z /A) / (Z /A)cr Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Discovery SF isomers Th JINR, Dubna, 1962 U neutron capture Pu HI-fusion 20 Cm 1030 Cf Fm 10 /s 102 SF T g o 104 L 0 Am LD -10 U mf Cm 33 SF-isomers mfPu -20 0.80 0.85 0.90 22 Fissility x = (Z /A) / (Z /A)cr Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark ShellShells and magic numbers and magic numbers NEW SHELLS E. Wigner/ M. Goeppert-Mayer /H. Jensen ? Nobel Prize 1963 About 3000 nuclei are known today Z=82 82 126 100Sn 208Pb protons 50 50 Among them 56 Ni 82 9 nuclei are doubly magic 132 28 28 Sn 50 20 20 4He 8 28 70Ni 2 20 40Ca neutrons 8 48Ca 2 16O Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Map of the shell corrections (in MeV) to the liquid drop potential energy 298114 Number of protons 208Pb Number of protons Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Uranium 8 8 E 6 LD 6 4 4 2 6 MeV Super heavy nucleus 2 ?19 0 1022 y 0 1010-19 ss 0 -2 -2 -4 E -4 LD al energy /al MeV energy -6 -6 -8 EShell -8 Isomeric 0 state 0 -2 -2 -4 Nuclear poten -4 0.3 -6 EShell 16 -6 10 y -8 -8 Ground state ELD+ Eshell 0 Nuclear deforma on -2 -4 ELD+ Eshell -6 -8 Nuclear deforma on Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark R. Smolańczuk, Phys. Rev. C 56 (1997) 812 Partial Spontaneous Fission Half-Lives SHE 20 Z=112 114 116 с 10 SF / seconds LogT / SF 0 Log T -10 МЖКLDM -20 0.70 0.75 0.80 0.85 0.90 0.95 ПараметрParameter делимости of fissility xx Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Half-lives Microscopic theory -5NewNew landslands 0 5 10 15 LogT1/2 s 1μs 1s 1h d 1Myear Island of 120 StabilityIsland of Stability Shoal 110 shoal Proton number Peninsula 100 peninsula 90 Continentcontinent Sea of Instability 80 70 100 110 120 130 140 150 160 170 180 190 Neutron number Experimenters rushed to find this island 15-year long assault on the “Islands of Stability” Los Alamos (USA) 1970-1985 Berkeley (USA) Dubna (JINR) Oak Ridge (USA) Mainz (Germany) Darmstadt (Germany) Orsay (France) Würenlingen (Switzerland) Tokyo (Japan) some later The task was: To find the method of producing/detecting of superheavy elements Search in nature: earth/lunar objects, cosmic rays, artificial synthesis of superheavy elements Use and develop a setup for synthesizing SHE High-flux reactor, even nuclear explosion, powerful accelerator of heavy ions, To develop setups and detectors for separating and registering the rarest events of formation and decay of superheavy nuclei separator/detector, spectrometer, chemical methods, etc. To have much patience To work for many years, being ready to rearrange on the way and improve the experimental technique Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark The task was: To find the method of producing/detecting of superheavy elements Search in nature: earth/lunar objects, cosmic rays, artificial synthesis of superheavy elements Use and develop a setup for synthesizing SHE High-flux reactor, even nuclear explosion, powerful accelerator of heavy ions, To develop setups and detectors for separating and registering the rarest events of formation and decay of superheavy nuclei separator/detector, spectrometer, chemical methods, etc. To have much patience To work for many years, being ready to rearrange on the way and improve the experimental technique Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Reactions of synthesis 114 r island of e b stability of superheavy m nuclei u n n o t o shoal of r deformed p nuclei 108 N Th U 90 Pu WN NE W peninsula Pb SW continent 126142 146162 neutron number 184 Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Reactions of synthesis Cold fusion 114 r island of e b Nh stability of superheavy m nuclei u Light ions n n o t o shoal of r deformed p nuclei 108 N Th U 90 Pu WN NE W peninsula Pb SW continent Neutron target capture 126from the142 146162 neutron number 184 “continent” Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark Our new approach greatly complicates the experiment Act.+48Ca 114 r island of e b stability of superheavy m nuclei u n n o t o shoal of r deformed p nuclei 108 target from N Th U“peninsula” 90 Pu WN NE W peninsula Pb SW continent 126142 146162 neutron number 184 Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark artificial element from flux nuclear reactor target from 48 244 to separator accelerator Ca Pu projectiles rare and very expensive isotope of Ca Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark artificial element from flux nuclear reactor target from 48244 to separator accelerator CaPu projectiles rare and very expensive isotope of Ca Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark artificial element from flux nuclear reactor target 292 from 48244 to separator accelerator CaPuFl projectiles rare and very expensive isotope of Ca Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark artificial element from flux nuclear reactor n target 292 from 48244 to separator accelerator CaPuFl projectiles n rare and very expensive isotope of Ca Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark artificial element from flux nuclear reactor n target 292288 from 48244 to separator accelerator CaPuFlFl projectiles n rare and very expensive isotope of Ca Yuri Oganessian. Discovery of the Island of Stability for SHE. May 19, 2017, Copenhagen, Denmark artificial element from flux nuclear reactor n target 292 288 from 48244 to separator accelerator CaPuFl Fl projectiles n rare and very expensive isotope of Ca Yuri Oganessian.
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