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Комитет Полномочных Представителей 26 ноября 2010 г., г.Дубна

Комитет Полномочных Представителей 26 ноября 2010 г., г.Дубна. ИДЕНТИФИКАЦИЯ И ИЗУЧЕНИЕ ХИМИЧЕСКИХ СВОЙСТВ НОВЫХ ЭЛЕМЕНТОВ ПЕРИОДИЧЕСКОЙ ТАБЛИЦЫ Д.И. МЕНДЕЛЕЕВА. С.Н. Дмитриев. 1. 2. 3. 4. Трансурановые элементы. 93 ≤ Z ≤ 100: Np, Pu, Am, Cm, Bk, Cf, Es, Fm

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Комитет Полномочных Представителей 26 ноября 2010 г., г.Дубна

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  1. Комитет Полномочных Представителей 26 ноября 2010 г., г.Дубна ИДЕНТИФИКАЦИЯ И ИЗУЧЕНИЕ ХИМИЧЕСКИХ СВОЙСТВ НОВЫХ ЭЛЕМЕНТОВ ПЕРИОДИЧЕСКОЙ ТАБЛИЦЫ Д.И. МЕНДЕЛЕЕВА С.Н. Дмитриев 1

  2. 2

  3. 3

  4. 4

  5. Трансурановые элементы 93 ≤ Z ≤ 100: Np, Pu, Am, Cm, Bk, Cf, Es, Fm Md→118 – реакции с тяжелыми ионами

  6. ХИМИЯ ТРАНСАКТИНОИДОВ (Z>103) • 1966 г. – И. Звара и др. (ЛЯР ОИЯИ, Дубна) HfCl4 TaBr5WO2Cl2 104Cl4 105Br5106O2Cl2 • Газоваяхимия(gas-phase chemistry) • (Летучесть галогенидов, оксигалогенидов) • Термохроматография (of-line) • Изотермическаяхроматография • (OLGA: On-Line Gas chromatography) 6

  7. ХИМИЯ ТРАНСАКТИНОИДОВ Aqueous-phase Chemistry 1980 г. – Хьюлет и др.; D.Hoffman и др. 261Rf (78 сек) - экстракция RfClx аминами - сорбция катионитами RfHfZr - экстракция ТВР, TIOA ARCA (Automated Rapid Chemistry Apparatus) 263Db – 27 сек жидкостная хроматография DbTaNb SISAK (Short-lived Isotopes Studied by the AKufve technique) многоступенчатая жидкостная экстракция на высокоскоростных микроцентрифугах (257Rf – 4 сек) 104 7

  8. ХИМИЯ ТРАНСАКТИНОИДОВ 8

  9. ACCELERATORS ISOTOPE ENRICHMENT TARGET TECHNOLOGY NEW RECOIL SEPARATOR REACTOR REGIME Efforts focused on the synthesis of SHE New ECR-ion source (GANIL, JINR) Enrichment up to 68-70% (Lesnoy) 48Ca technology of the target preparation – 0.3mg/cm2 Separation and detection of superheavy nuclei New separator & detectors (Dubna, Livermore) isotope enrichment 98-99% S-2 separator (Sarov) New target matter isotope production high flux reactors (Oak Ridge, Dimitrovgrad) 9

  10. ЦИКЛОТРОН У400 10

  11. Карта нуклидов

  12. Dmitriev S N et al., Mendeleev Commun.15(2005) 1 Schumann D et al., Radiochim. Acta 93(2005) 727 Stoyer N J et al., Proc.9th Int. Conf. NNCollisions,Brazil, 28 Aug.–1 Sep. 2006. Z=115 Transactinides Nb / Ta / Db - fraction Of-line chemical separation of 268Db Oganessian Yu Ts et al., Phys. Rev. C 69 (2004)021601 ~20 s

  13. 48Ca + 243Am 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3,4.1018 15 events

  14. 15 events Spontaneous fission half-life of 268Db (N=163) T1/2 = 32 h 268Db 252Cf QF ~ 280 MeV 14

  15. Conclusion • The properties of the isotope 268Db produced in the decay chain of element 115 using the gas-filled recoil separator agree by all measured parameters with the data of the present chemical experiment on the determination of its atomic number. • The decay chain of element 115 synthesized in the reaction 243Am+48Ca consists of 5 sequential -transitions resulting in the formation of the long-lived nucleus of element 105 leading to spontaneous fission. A hypothesis of the possible -decay of the Db nucleus has been totally rejected by the conditions of chemical separation of the reaction products in this experiment. • Thus, the data from the present experiment are the independent evidence for the synthesis of element 115 as well as element 113 in the reaction243Am+48Ca 15

  16. Карта нуклидов

  17. contraction and stabilization of s and p1/2orbitals expansion and destabilization of d andforbitals SO splitting of p, d, forbitals j = l s Relativistic effects Re(7s) = 20% scale as ~ Z2

  18. GAS PHASE CHEMISTRY WITH ELEMENTS 112 AND 114 Are elements 112 and 114 volatile metals? How do relativistic effects influence the chemistry of E112 and of E114? 18

  19. How to experimentally determine a metallic character of a volatile element at a single atom level? → Determine interaction energy (adsorption enthalpy) with noble metals (e.g. Au) → If metallic: strong interaction (adsorption enthalpy) if non-metallic (noble gas like): weak interaction 19

  20. Compound Hg(Au) and 112(Au) Reaction: 242Pu(48Ca,3n)287114[0.5s]→α→283112[3.6s]

  21. Reported at FLNR: Oganessian et al. 2004 291116 6.3 ms 10.7 MeV 287114 0.51 s 10.02 MeV 283112 4 s 9.54 MeV on ice on gold -5°C -26°C -24°C -44°C -126°C 279Ds 0.18 s SF(>90%) 205 MeV The Observation Dubna2006/2007 5 weeks: 6*1018 48Ca 242Pu (48Ca, 3n) 287114 Observed in Chemistry: Experiments with element 112 Eichler, R. et al. Nature (2007)

  22. Results (-24°C) (-5°C) (-26°C) (-44°C) (-127°C) Experiment Simulation gas flow Experiments with element 112

  23. Тенденции изменения летучести элементов II б группы Периодической таблицы Д.И.Менделеева ∆H субл. ∆H субл., кДж/моль T кип., К T кип. 23

  24. 287114 0.51 s 10.02 MeV 287114 10.04 MeV 283112 4.0 s 9.54 MeV 283112 10.9 s 9.53 MeV 279Ds 0.18 s SF 279Ds 0.24 s SF 48Ca + 242Pu Физическийэксперимент Химический эксперимент Тадс=-88 °C

  25. 288114 9.95 MeV 284112 t:109 ms SF 48Ca + 244Pu Физическийэксперимент Химический эксперимент 288114 0.8 s 9.95 MeV Тадс=-84 °C 284112 101 ms SF

  26. Tdep: -88°C Tdep: -4°C -84°C Tdep: -93°C Preliminary Results Dubna 2007/2008 ice gold Experiments with element 114

  27. Result from the chemistry experiment with element 114 → Element 114 exhibits a very weak interaction with Au - pointing to a physisorptive interaction (similar to a noble gas). →A quantitative description of this behaviour is lacking so far. 27

  28. 28

  29. Synthesis of a new element with atomic number Z=117 Yu. Ts. Oganessian,1) F. Sh. Abdullin,1) P. D. Bailey,2) D. E. Benker,2) M. E. Bennett,3)S N. Dmitriev,1) J. G. Ezold,2) J. H. Hamilton,4) R. A. Henderson,5) M. G. Itkis,1) Yu. V. Lobanov,1) A. N. Mezentsev,1) K. J. Moody,5)S. L. Nelson,5) A.N. Polyakov,1) C. E. Porter,2) A. V. Ramayya,4) F. D. Riley,2) J. B. Roberto,2) M. A. Ryabinin,6)K. P. Rykaczewski,2) R. N. Sagaidak,1) D. A. Shaughnessy,5) I.V. Shirokovsky,1) M. A. Stoyer,5)V. G. Subbotin,1)R. Sudowe,3)A. M. Sukhov,1) Yu. S. Tsyganov,1) V. K. Utyonkov,1) A. A. Voinov,1) G. K. Vostokin,1) and P. A. Wilk5) 1Joint Institute for Nuclear Research, RU-141980 Dubna, RF 2Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 3University of Nevada Las Vegas, Las Vegas, NV 89154, USA 4Vanderbilt University, Nashville, TN 37235, USA 5Lawrence Livemore National Laboratory, Livermore, CA 94551, USA 6Research Institute of Atomic Reactors, RU-433510 Dimitrovgrad, RF (Dated: April 1, 2010) The discovery of a new chemical element with atomic number Z=117 is reported. The isotopes 293117 and 294117 were produced in fusion reactions between 48Ca and 249Bk. Decay chains involvingeleven new nuclei were identified by means of the Dubna Gas Filled Recoil Separator. The measureddecay properties show a strong rise of stability for heavier isotopes with Z≥111, validating theconcept of the long sought island of enhanced stability for super-heavy nuclei 30

  30. CHEMISTRY OF THE 113ELEMENT Target (249 Bk; 0,5 mg/cm2) (4) SiO2- Ta 800°C Au - 113 16 pairs 2.5m 1 L/min He/Ar (70/30) 31

  31. Capillary length from target chamber to detector system is 2.5 m 32

  32. 16 pairs of gold covered detectors 33

  33. 48Ca + 249Bk Target 249Bk (0.5 mg∙cm-2) natNd (30 μg∙cm-2) 48Ca Emid. target = 252 MeV I ~ 9 eμA Irradiation: - 18.04.2010 – 31.05.2010; target I - 3.5 1018 ; target II - 5.6 1018 9.1∙1018 34

  34. Hg-185 DISTRIBUTION 35

  35. Alpha and SF spectra 36

  36. 112 ms 45 ms 21 ms 10 ms 297 297 294 293 117 117 117 117 α1 α1 288 115 11.03(8) MeV 11.26 MeV 10.81(10) MeV 11.00 MeV 0.023 s 1.0 s 0.32 s 0.22 s 289 290 115 115 10.46 MeV 87 ms α2 α2 3n 284 9.95(40) MeV 10.23 MeV 10.31(9) MeV 10.48 MeV 113 243Am + 48Ca 7.9 s 1.2 s 28.3 s 16 s 285 286 113 113 10.00 MeV 0.48 s α3 α3 280 α1 9.74(8) MeV 9.48(11) MeV 9.96 MeV 9.63(10) MeV 9.56 MeV Rg 0.74 s 8.1 s 282 281 Rg Rg 9.75 MeV 3.6s α4 276 Mt 9.00(10) MeV 9.43 MeV 11.0 s 13 s SF 278 α2 Mt 9.71 MeV 0.72s TKE = 218(5) MeV 38s α5 272 Bh 9.55(19) MeV 9.14 MeV 1.3 min 7.4 min 274 Bh 9.02 MeV 9.8 s α6 268 α3 8.80(10) MeV 8.43 MeV Db 270 Db SF TKE = 205(5) MeV 16 h SF α4 TKE = 219(5) MeV 33.4h α5 Chemistry of the Element 113 249Bk + 48Ca DGFRS 37

  37. 112 ms 45 ms 297 294 117 117 α1 10.81(10) MeV 11.00 MeV 0.023 s 1.0 s 290 115 α2 9.95(40) MeV 10.23 MeV 28.3 s 16 s 286 113 α3 9.63(10) MeV 9.56 MeV 0.74 s 8.1 s 282 Rg α4 9.00(10) MeV 9.43 MeV 11.0 s 13 s 278 Mt α5 9.55(19) MeV 9.14 MeV 1.3 min 7.4 min 274 Bh α6 8.80(10) MeV 8.43 MeV 270 Db SF TKE = 219(5) MeV 33.4h 3n 249Bk + 48Ca 294 117 α1 290 115 α2 286 113 α3 Top 4 282 Rg α4 9.01 MeV 1.85min 278 Mt α5 Bot. 4 274 Bh α6 8.64 MeV <1.42min 270 Db СД 98.6 + 88.5 MeV 64.61h E* = 35 MeV 1 event Top 4 9.61 MeV DGFRS 16 May 2010 02:29:54 Bk-target II 38

  38. D 400mg/cm2 244Pu DGFRS Q1 Q2 COLD -160°C 10°C Preliminary Results Dubna 2008 244Pu (48Ca, 3-4n)288-289114 Recoil ranges tested with: 206Rn, 185Hg, 254No  Reliable design: 3 mm Mylar, 1.5 cm Ar (1 bar) Experiments with element 114 Gas flow: Ar 2.1 l/min ttrans~1.4 s

  39. Preliminary Results Dubna 2007/2008 No preseparation DGFRS preseparation  Factor ~2-3 loss in overall efficiency:  thin targets (2-3)  transmission separator (3)  higher beam doses (1.5)  shorter transport time (2)

  40. Chemistry behind the gas-filled separator

  41. 112 ms 45 ms 297 294 117 117 α1 10.81(10) MeV 11.00 MeV 0.023 s 1.0 s 290 115 α2 3n 249Bk + 48Ca 9.95(40) MeV 10.23 MeV 294 28.3 s 16 s 286 117 113 α3 α1 9.63(10) MeV 9.56 MeV 0.74 s 8.1 s 282 Rg α4 290 9.00(10) MeV 9.43 MeV 115 11.0 s 13 s 278 α2 Mt α5 9.55(19) MeV 9.14 MeV 1.3 min 7.4 min Bot. 8 274 286 Bh 113 α6 α3 8.80(10) MeV 8.43 MeV 270 9.62 MeV Db Bot. 8 282 SF Rg α4 TKE = 219(5) MeV 33.4h 8.89 MeV 64.90 s Bot. 8 278 Mt α5 9.52 MeV 6.49 s Bot. 8 274 Bh α6 8.77 MeV 13.59 min 270 Db SF 101.0 + 89.1 MeV 79.25 h 3n 249Bk + 48Ca 294 117 α1 290 115 α2 286 113 α3 Top 4 282 Rg α4 9.01 MeV 1.85min 278 Mt α5 Bot. 4 274 Bh α6 8.64 MeV <1.42min 270 Db SF 98.6 + 88.5 MeV 64.61h E* = 35 MeV 1 event preliminary DGFRS 04 May 2010 10:05:4616 May 2010 02:29:54 Bk-target I Bk-target II 30.08.2014 42 108 session of JINR SC

  42. STATUS of the MASS-SPECTROMETER Mass-spectrometer MASHA at the beam line of the cyclotron U-400M

  43. FIRST EXPERIMENTS • Mass identification of 112 и 114 elements synthesizedat the reactions • 242Pu(48Ca,3n)287114(0.5 s) –> 283112(4 s) • Mass identification of 113elements synthesizedat the reaction • 243Am(48Ca,3n)288115 (0.1 s) →284113 (0.5 s)

  44. NEW EXPERIMENTAL HALL

  45. Z=114 N=184 T1/2109 y 110-115 (eka Pt – eka Bi) • Theoretical prediction of chemical properties • Search of SHE in Nature • Geological samples (high concentration of possible homologues) • Meteorites (Allende, Efremovka) • Thermal Waters (hot brines, rift zone) • Solid-State Detectors • Big Proportional Counters Spontaneous fission fragments • 3He-filled counters • Liquid scintillators Neutron multiplicaties T1/2109 10-13 – 10-14 g/g SEARCH of SUPERHEAVY ELEMENTS in NATURE

  46. 20 20 Возраст Земли 108y Поиски СТЭ в природе 15 15 Поиск СТЭ в космических лучах 105y ) ы д a - распад н 10 у к 108 1y е с ( a 110 T g 5 o L 112 114 1 s 0 116 118 118 -5 108 108 Act,+48Ca 110 110 112 -10 Cold fusion 116 114 114 140 150 170 180 190 160 Число нейтронов Теория и эксперимент

  47. ПОИСК СТЭ Fréjus peak Вход в тоннель Modane Франция Италия 1 SF– события в год (T1/2=109y) соответствующий: 108/Os = 5.10-15г/г и 108/Os = 5.10-19г/г приT1/2≤105y Xe – 140 г – 1 SF в месяц 48

  48. БЛАГОДАРЮ ЗА ВНИМАНИЕ!

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