2. Chemistry of Spherical Superheavy Elements – The Road to Success

3. sea of instability island of spherical SHE Number of neutrons Number of protons 20 50 82 114 20 82 126 184 peak of Sn peak of Ca peak of Pb peak of Th,U strait of radioactivity S. Soverna January 2004

4. 287   5 s 114 168 283 sf  3 min 112 170 Hs 277 sf  10  min 285   10 min 112 281   1 min Ds 289   20 s 114 172 174 114 284   45 s 112   2.6 s 114 288 280 sf  7.6 s Ds 292   53 ms 116 Rf 253 sf 48  s Rf 254 sf 23  s Rf 256 sf,  6.2  s Rf 257 ,ec 4.7s ,ec Rf 258 sf 13 ms Rf 259 ,sf 3.1 s Rf 260 sf 21 ms Rf 261  78 s Rf 262 sf 47ms 1.4s Rf 255 ,sf 0.8s ,sf 1.4s2.1s sf Db 257 ,sf 1.3 s Db 258 ,ec 4.4 s Db 260 ,ec/sf? 1.5 s Db 261 ,sf 1.8 s Db 262 ,ec/sf? 34 s Db 263 ,sf 27 s Sg 265 ,sf? 7.4 s Sg 266 ,sf? 21 s 1.4s Sg 263  0.3s ,sf? 0.9s Sg 261 ,ec 0.23 s Sg 260 ,sf 3.6 ms Sg 259  0.48 s Sg 258 sf 2.9 ms Bh 261  11.8 ms Bh 264  440 ms Bh 262  102ms  8ms Db 256 ,sf 2.6 s Db 255 ,sf 1.6 s Bh 260  ? Hs 263  ? Hs 264 ,sf 0.45 ms Hs 265  0.8ms  1.7ms  Hs 267 59 ms Hs 269   9.3 s Mt 266  1.7 ms Mt 268  70 ms Ds 267   3  s Ds 271  1.1ms  56 ms Ds 273  291  s 269  170  s Ds 272  1.6 ms 111 112 277  194  s  277  s Rf Ruther- fordium Db Dubnium Sg Seaborgium Bh Bohrium Hs Hassium Mt Meitnerium Ds 111 112 105 106 107 110 109 108 112 111 150152154156158 160 164 N 166 Z Bh 266   1s Bh 267   17 s Hs 266 2.3 ms  Sg 262 sf 6.9 ms Ds 270  0.1ms  6 ms Db 259,ec/sf? 0.5 s  Hs 270   3.6 s 116116 118118   87 ms 115 288   32 ms 115 287 284   0.48 s 113 283   100 ms 113 280   3.6 s 111 279   170 ms 111 276   0.72 s Mt 275   9.7 ms Mt 272   9.8 s Bh 271  Bh 268   16 h Db 267   73 m Db 290   30 ms 116 286   0.4 s 114 294  sf  2 ms 118 113113 115115 Evidence for long-lived isotopes from 48 Ca induced fusion reactions on actinide targets (FLNR, published and unpublished data)  -Decay Spontaneous fission EC-Decay Darmstadtium, sf  7.9 s

5. - Half-lives of primary evaporation residues and their progenies: ms to h (Chemistry needs ≥ s) - Decay properties: mostly  -decay chains ending in a SF-nuclide (Problem: No link to known nuclides) - Maximum production cross sections  1 to 5 pb (3n and 4n channels). For 1 mg/cm 2 targets and 0.5 p  A beam approx. 0.6 to 3 atoms/day produced (Problem: UNILAC duty cycle, cw beam would enable approx. factor of 3 higher intensity at equal peak current)

6. The missing link: 287   5 s 114 168 283 sf  3 min 112 170 Hs 277 sf  10  min 285   10 min 112 281   1 min Ds 289   20 s 114 172 174 114 284   45 s 112   2.6 s 114 288 280 sf  7.6 s Ds 292   53 ms 116 Rf 253 sf 48  s Rf 254 sf 23  s Rf 256 sf,  6.2  s Rf 257 ,ec 4.7s ,ec Rf 258 sf 13 ms Rf 259 ,sf 3.1 s Rf 260 sf 21 ms Rf 261  78 s Rf 262 sf 47ms 1.4s Rf 255 ,sf 0.8s ,sf 1.4s2.1s sf Db 257 ,sf 1.3 s Db 258 ,ec 4.4 s Db 260 ,ec/sf? 1.5 s Db 261 ,sf 1.8 s Db 262 ,ec/sf? 34 s Db 263 ,sf 27 s Sg 265 ,sf? 7.4 s Sg 266 ,sf? 21 s 1.4s Sg 263  0.3s ,sf? 0.9s Sg 261 ,ec 0.23 s Sg 260 ,sf 3.6 ms Sg 259  0.48 s Sg 258 sf 2.9 ms Bh 261  11.8 ms Bh 264  440 ms Bh 262  102ms  8ms Db 256 ,sf 2.6 s Db 255 ,sf 1.6 s Bh 260  ? Hs 263  ? Hs 264 ,sf 0.45 ms Hs 265  0.8ms  1.7ms  Hs 267 59 ms Hs 269   9.3 s Mt 266  1.7 ms Mt 268  70 ms Ds 267   3  s Ds 271  1.1ms  56 ms Ds 273  291  s 269  170  s Ds 272  1.6 ms 111 112 277  194  s  277  s Rf Ruther- fordium Db Dubnium Sg Seaborgium Bh Bohrium Hs Hassium Mt Meitnerium Ds 111 112 105 106 107 110 109 108 112 111 160 164 N 166 Z Bh 266   1s Bh 267   17 s Hs 266 2.3 ms  Sg 262 sf 6.9 ms Ds 270  0.1ms  6 ms Db 259,ec/sf? 0.5 s  Hs 270   3.6 s 116116 118118   87 ms 115 288   32 ms 115 287 284   0.48 s 113 283   100 ms 113 280   3.6 s 111 279   170 ms 111 276   0.72 s Mt 275   9.7 ms Mt 272   9.8 s Bh 271  Bh 268   16 h Db 267   73 m Db 290   30 ms 116 286   0.4 s 114 294  sf  2 ms 118 113113 115115  -Decay Spontaneous fission EC-Decay Darmstadtium, sf  7.9 s Hs chemistry, a tool to bridge the gap A. Türler et al.

7. - Half-lives of primary evaporation residues and their progenies: ms to h (Chemistry needs ≥ s) - Decay properties: mostly  -decay chains ending in a SF-nuclide (Problem: No link to known nuclides) - Maximum production cross sections  1 to 5 pb (3n and 4n channels). For 1 mg/cm 2 targets and 0.5 p  A beam approx. 0.6 to 3 atoms/day produced (Problem: UNILAC duty cycle, cw beam would enable approx. factor of 3 higher intensity at equal peak current)

8. S. Soverna January 2004

9. 0 8060 40 20 120100 0 20 40 60 80 100 120 Standard enthalpies of gaseous mono- atomic elements Atomic number  H ° 298 [kcal/mol] B. Eichler, 1976 Conclusion: Elements 112 to 117 should be volatile noble metal-like elements Problem: Influence of relativistic effects?

10. Relativistic Extrapolations K.S. Pitzer, J. Chem. Phys. 63, 1032 (1975) V. Pershina et al., Chem. Phys. Lett., 365, 176 (2002) B. Eichler, Kernenergie 10, 307 (1976 ) B. Eichler, PSI Report 03-01, Villigen (2000) Noble gas like Volatile metal

11. How to experimentally determine a metallic character at a single atom level? → Determine interaction energy (adsorption enthalpy) with (noble*) metals, i.e. measure retention temperature * Easier to keep clean surface during experiment

12. isothermal chromatography Temperature [°C] Column length [cm] Temperature [°C] Yield [%] 50% T t Ret. = T 1/2 Gas flow highlow thermochromatography Temperature [°C] Column length [cm] Temperature [°C] Yield [%] T a high Gas flow low

13. R. Eichler et al.

14. Current interest: element 112 → Behaves E112 similar to Hg ? → Production: 238 U( 48 Ca;3n) 283 112 (SF;T 1/2  3 min) → 2 chemistry experiments performed with evicence for: At FLNR: Isothermal chromatography on Au: E112 does not adsorb at room temp.  H a < 60 kJ/mol (A. Yakushev et al.) At GSI: Thermochromatography: E112 does not deposit on Au down to -90 °C  H a < 48 kJ/mol (S. Soverna et al.)

15. 238 U( 48 Ca,3n) 283 112  20 s 8.7-8.9 sf 112 283 3 m  20 s 8.7-8.9 112 EVR 286  20 s 8.7-8.9 sf 112 283 0.9 m  20 s 8.7-8.9 112 EVR 286  20 s 8.7-8.9 sf 112 283 24.3 m  20 s 8.7-8.9 112 EVR 286  20 s 8.7-8.9 sf 112 283 3 m  20 s 8.7-8.9 112 EVR 286 VASSILISSA E* 33 MeV E* 35 MeV Oganessian et al., 1999 & in press

16. Current interest: element 112 → Behaves E112 similar to Hg ? → Production: 238 U( 48 Ca;3n) 283 112 (SF;T 1/2  3 min) → 2 chemistry experiments performed with evicence for: At FLNR: Isothermal chromatography on Au: E112 does not adsorb at room temp.  H a < 60 kJ/mol (A. Yakushev et al.) At GSI: Thermochromatography: E112 does not deposit on Au down to -90 °C  H a < 48 kJ/mol (S. Soverna et al.)

17. Ar +CH 4 mixture 48 Ca He inlet He outlet He Gas outlet Chemical isolation of Element 112 Target: U 3 O 8 - 2mg/cm 2 + Nd 2 O 3 - 50  g/cm 2 Beam: 48 Ca (262 MeV) 0.6 p  A Dose: 2.8x10 18 ; 8 SF detected in ion.chamber in coincidence with 1 to 3 neutrons

18. Current interest: element 112 → Behaves E112 similar to Hg ? → Production: 238 U( 48 Ca;3n) 283 112 (SF;T 1/2  3 min) → 2 chemistry experiments performed with evicence for: At FLNR: Isothermal chromatography on Au: E112 does not adsorb at room temp.  H a < 60 kJ/mol (A. Yakushev et al.) At GSI: Thermochromatography: E112 does not deposit on Au down to -90 °C  H a < 48 kJ/mol (S. Soverna et al.)

19. oven (1000 °C) Ta-/Ti-getter quartz wool filter oven (850 °C) ~10 m PFA-capillary 48 Ca-Beam recoil chamber rotating 238 U-target (1.6 mg cm -2 ) PIN-dioden oppositer thermostat surface N 2 (liq.) (-196 °C) (+35 °C) a S. Soverna January 2004

20. Experiment GSI February-March 2003 238 U( 48 Ca, 3n) 283 112 (SF, 3min) 283 112

21. Both experiments not conclusive, because → Detection of SF activity not specific to assign it to a given (isotope of an) element. → Fission fragment energies too low (FLNR: ion. chamber; GSI: PIN- diodes)

22. Current effort: focus on  - decaying nuclides

23. V. Utyonkov, priv. comm. Feb. 2004 48 Ca + 238 U @ DGFRS/FLNR

24. Device 2004 Ar/He carrier gas loop (v=10 l) Ar - refill 48 Ca beam Recoil chamber (volume approx.10 cc Buffer Getter oven Pressure gauge / MFC 4-  COLD, 1 side gold All metal Rn Trap Mass flow controller

25. Requirements for future SHE chemistry experiments (e.g. Z=114) - Fast (separation time approx. 1 s) - Separation of transfer products prior to chemistry set-up: ChemSep - Chemistry behind a ChemSep - Beam dose of ≥ 10 19 required for approx. 1 month experiments: 1 p  A average beam intensity! cw-LINAC; Novel target technology (stable compounds, liquid metal targets)

26. DGFRS 1 x Ds 179 sf 0.31 s  20 s 8.7-8.9 114 EVR 290  20 s 8.7-8.9 112 283 5.4 s  9.5  20 s 8.7-8.9 114 287 1.5 s  10 244 Pu( 48 Ca,5n) 287 114 E* 52 MeV 242 Pu( 48 Ca,3n) 287 114  20 s 8.7-8.9 114 EVR 290 Ds 179 0.28 s  9.7  20 s 8.7-8.9 112 283 7.8 s  9.5  20 s 8.7-8.9 Hs 275 422 ms  9.3  20 s 8.7-8.9 sf Sg 271 6.3 m  20 s 8.7-8.9 114 287 1 s  10 Ds 179 sf 0.2 s  20 s 8.7-8.9 114 EVR 290  20 s 8.7-8.9 112 283 4 s  9.5  20 s 8.7-8.9 114 287 1 s  10 16 x1 x E* 40 MeV E* 32-52 MeV 245 Cm( 48 Ca,2n) 291 116  20 s 8.7-8.9 112 283 8.57 s  20 s 8.7-8.9 116 EVR 293  9.5  20 s 8.7-8.9 116 291 8 ms  10.75  20 s 8.7-8.9 114 287 1 s  10 Ds 179 sf 0.2 s 2 x E* 35 MeV

27. Reqiurements for future SHE chemistry experiments - Fast (separation time approx. 1 s) - Separation of transfer products prior to chemistry set-up: ChemSep - Chemistry behind a ChemSep - Beam dose of ≥ 10 19 required for approx. 1 month experiments: 1 p  A average beam intensity! cw-LINAC; Novel target technology (stable compounds, liquid metal targets)

28. 220 Rn 48 Ca + 248 Cm H.W. Gäggeler et al., Phys. Rev. C33, 1983 (1986) Transfer reaction products!

29. Requirements for future SHE chemistry experiments - Fast (separation time approx. 1 s) - Separation of transfer products prior to chemistry set-up: ChemSep - Chemistry behind a ChemSep - Beam dose of ≥ 10 19 required for approx. 1 month experiments: 1 p  A average beam intensity! cw-LINAC; - Novel target technology (stable compounds, liquid metal targets)

30. A recoil/gas chemistry chamber at the Berkeley Gas-filled Separator (BGS)

31. Hot-catcher coupled to vacuum thermochromatography set-up Induction heating SHE@CHEMSEP Hot Catcher R. Eichler, Qin Zhi 

32. R.Eichler, Qin Zhi

33. Requirements for future SHE chemistry experiments - Fast (separation time approx. 1 s) - Separation of transfer products prior to chemistry set-up: ChemSep - Chemistry behind a ChemSep - Novel target technology (stable compounds, liquid metal targets) - Beam dose of ≥ 10 19 required for approx. 1 month experiments: 1 p  A average beam intensity! cw-LINAC;

34. Suggested application: liquid U/Mn (80/20) at 700 °C

35. Requirements for future SHE chemistry experiments - Fast (separation time approx. 1 s) - Separation of transfer products prior to chemistry set-up: ChemSep - Chemistry behind a ChemSep - Novel target technology (stable compounds, liquid metal targets) - Beam dose of ≥ 10 19 required for approx. 1 month experiments: 1 p  A average beam intensity! (cw-LINAC)