Chemistry of Spherical Superheavy

Elements – The Road to Success

sea of instability

sea of instability

island of spherical

SHE

Number of neutrons

Nu

mb

er

of

pro

ton

s

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. SovernaJanuary 2004

287

5 s114

168168

283

sf 3 min

112

170170

Hs277

sf10min

285

10 min

112

281

1 min

Ds

289

20 s114

172172

174174

114114114

284

45 s

112

2.6 s

114288

280

sf 7.6 s

Ds

292

53 ms

116

Rf253

sf48 s

Rf254

sf23 s

Rf256

sf,6.2 s

Rf257

,ec4.7s,ec

Rf258

sf13 ms

Rf259

,sf3.1 s

Rf260

sf21 ms

Rf261

78 s

Rf262

sf47ms1.4s

Rf255

,sf0.8s

,sf1.4s 2.1s

sf

Db257

,sf1.3 s

Db258

,ec4.4 s

Db260

,ec/sf?1.5 s

Db261

,sf1.8 s

Db262

,ec/sf?34 s

Db263

,sf27 s

Sg265

,sf?7.4 s

Sg266

,sf?21 s1.4s

Sg263

0.3s

,sf?0.9s

Sg261

,ec0.23 s

Sg260

,sf3.6 ms

Sg259

0.48 s

Sg258

sf2.9 ms

Bh261

11.8 ms

Bh264

440 ms

Bh262

102ms

8ms

Db256

,sf2.6 s

Db255

,sf1.6 s

Bh260

?

Hs263

?

Hs264

,sf0.45 ms

Hs265

0.8ms

1.7ms

Hs26759 ms

Hs269

9.3 s

Mt266

1.7 ms

Mt268

70 ms

Ds267

3 s

Ds271

1.1ms

56 ms

Ds273

291 s

269

170 s

Ds

272

1.6 ms

111

112277

194s

277s

RfRuther-fordium

DbDubnium

SgSeaborgium

BhBohrium

HsHassium

MtMeitnerium

Ds

111

112

105105

106106

107107

110110

109109

108108

112112

111111

150150 152152 154154 156156 158158

160160

164164

NN

166166

ZZ

Bh266

1s

Bh267

17 s

Hs2662.3 ms

Sg262

sf6.9 ms

Ds270

0.1ms

6 ms

Db259

,ec/sf?0.5 s

Hs270

3.6 s

116116116

118118118

87 ms

115288

32 ms

115287

284

0.48 s

113283

100 ms

113

280

3.6 s

111279

170 ms

111

276

0.72 s

Mt275

9.7 ms

Mt

272

9.8 s

Bh271

Bh

268

16 h

Db267

73 m

Db

290

30 ms

116

286

0.4 s

114

294

sf 2 ms

118

113113113

115115115

Evidence for long-lived isotopesEvidence for long-lived isotopesfrom from 4848Ca induced fusionCa induced fusionreactions on actinide targetsreactions on actinide targets(FLNR, published and(FLNR, published andunpublished data)unpublished data)

--DecayDecay SpontanSpontaneous fissioneous fission EC-EC-DecayDecay

Darmstadtium

, sf7.9 s

- 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/cm2 targets and 0.5 pA 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)

The missing link:

287

5 s114

168168

283

sf 3 min

112

170170

Hs277

sf10min

285

10 min

112

281

1 minDs

289

20 s114

172172

174174

114114114

284

45 s

112

2.6 s114288

280

sf 7.6 s

Ds

292

53 ms

116

Rf253

sf48 s

Rf254

sf23 s

Rf256

sf,6.2 s

Rf257

,ec4.7s,ec

Rf258

sf13 ms

Rf259

,sf3.1 s

Rf260

sf21 ms

Rf261

78 s

Rf262

sf47ms1.4s

Rf255

,sf0.8s

,sf1.4s 2.1s

sf

Db257

,sf1.3 s

Db258

,ec4.4 s

Db260

,ec/sf?1.5 s

Db261

,sf1.8 s

Db262

,ec/sf?34 s

Db263

,sf27 s

Sg265

,sf?7.4 s

Sg266

,sf?21 s1.4s

Sg263

0.3s

,sf?0.9s

Sg261

,ec0.23 s

Sg260

,sf3.6 ms

Sg259

0.48 s

Sg258

sf2.9 ms

Bh261

11.8 ms

Bh264

440 ms

Bh262

102ms

8ms

Db256

,sf2.6 s

Db255

,sf1.6 s

Bh260

?

Hs263

?

Hs264

,sf0.45 ms

Hs265

0.8ms

1.7ms

Hs26759 ms

Hs269

9.3 s

Mt266

1.7 ms

Mt268

70 ms

Ds267

3 s

Ds271

1.1ms

56 ms

Ds273

291 s

269

170 s

Ds

272

1.6 ms

111

112277

194s

277s

RfRuther-fordium

DbDubnium

SgSeaborgium

BhBohrium

HsHassium

MtMeitnerium

Ds

111

112

105105

106106

107107

110110

109109

108108

112112

111111

160160

164164

NN

166166

ZZ

Bh266

1s

Bh267

17 s

Hs2662.3 ms

Sg262

sf6.9 ms

Ds270

0.1ms

6 ms

Db259

,ec/sf?0.5 s

Hs270

3.6 s

116116116

118118118

87 ms

115288

32 ms

115287

284

0.48 s

113283

100 ms

113

280

3.6 s

111279

170 ms

111

276

0.72 s

Mt275

9.7 ms

Mt

272

9.8 s

Bh271

Bh

268

16 hDb267

73 mDb

290

30 ms

116

286

0.4 s

114

294

sf 2 ms

118

113113113

115115115

--DecayDecay SpontanSpontaneous fissioneous fission EC-EC-DecayDecay

Darmstadtium

, sf7.9 s

Hs chemistry, a tool to bridge the gap

A. Türler et al.

- 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/cm2 targets and 0.5 pA 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)

1 181 2H 2 13 14 15 16 17 He3 4 5 6 7 8 9 10Li Be B C N O F Ne11 12 13 14 15 16 17 18Na Mg 3 4 5 6 7 8 9 10 11 12 Al Si P S Cl Ar19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe55 56 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86Cs Ba Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn87 88 104 105 106 107 108 109 110 111 112 113 114 115 116Fr Ra Rf Db Sg Bh Hs Mt Ds Uuu Uub Uut Uuq Uup Uuh

57 58 59 60 61 62 63 64 65 66 67 68 69 70 71La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu89 90 91 92 93 94 95 96 97 98 99 100 101 102 103Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

1230Zn48Cd80Hg112Uub

S. SovernaJanuary 2004

0 80604020 1201000

20

40

60

80

100

120

Standard enthalpies of gaseous mono-atomic elements Atomic

number

H° 2

98 [

kcal/m

ol]

B. Eichler, 1976

Conclusion: Elements 112 to 117 should be volatile noble metal-like elementsProblem: Influence of relativistic effects?

RelativisticExtrapolations

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 likeVolatile metal

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

iisothermsothermalal cchromatographhromatographyyT

emp

erat

ure

[°C

]

Column length [cm] Temperature [°C]

Yie

ld [

%]

50%TtRet. = T1/2

Gas flow

highlow

tthermochromatographhermochromatographyy

Tem

per

atu

re [

°C]

Column length [cm] Temperature [°C]

Yie

ld [

%]

Ta

high

Gas flow

low

R. Eichler et al.

Current interest: element 112→ Behaves E112 similar to Hg ?

→ Production: 238U(48Ca;3n)283112 (SF;T1/2 3 min)

→ 2 chemistry experiments performed with evicence for:

At FLNR: Isothermal chromatography on Au: E112 does not adsorb at room temp. Ha < 60 kJ/mol (A. Yakushev et al.)

At GSI: Thermochromatography: E112 does not deposit on Au down to -90 °C Ha < 48 kJ/mol (S. Soverna et al.)

238238U(U(4848Ca,3n)Ca,3n)283283112112

20 s8.7-8.9

sf

112283

3 m 20 s8.7-8.9

112

EVR

286

20 s8.7-8.9

sf

112283

0.9 m 20 s8.7-8.9

112

EVR

286

20 s8.7-8.9

sf

112283

24.3 m 20 s8.7-8.9

112

EVR

286

20 s8.7-8.9

sf

112283

3 m 20 s8.7-8.9

112

EVR

286

VASSILISSAVASSILISSA

E* 33 MeV

E* 35 MeV

Oganessian et al., 1999 & in press

Current interest: element 112→ Behaves E112 similar to Hg ?

→ Production: 238U(48Ca;3n)283112 (SF;T1/2 3 min)

→ 2 chemistry experiments performed with evicence for:

At FLNR: Isothermal chromatography on Au: E112 does not adsorb at room temp. Ha < 60 kJ/mol (A. Yakushev et al.)

At GSI: Thermochromatography: E112 does not deposit on Au down to -90 °C Ha < 48 kJ/mol (S. Soverna et al.)

Ar +CH4

mixture

48Ca

Heinlet

Heoutlet

He

Gasoutlet

Chemical isolation of Element 112

Target:U3O8- 2mg/cm2 + Nd2O3 - 50 g/cm2

Beam:48Ca (262 MeV)0.6 pA

Dose: 2.8x1018; 8 SF detected in ion.chamber in coincidence with 1 to 3 neutrons

Current interest: element 112→ Behaves E112 similar to Hg ?

→ Production: 238U(48Ca;3n)283112 (SF;T1/2 3 min)

→ 2 chemistry experiments performed with evicence for:

At FLNR: Isothermal chromatography on Au: E112 does not adsorb at room temp. Ha < 60 kJ/mol (A. Yakushev et al.)

At GSI: Thermochromatography: E112 does not deposit on Au down to -90 °C Ha < 48 kJ/mol (S. Soverna et al.)

oven

(1000 °C)

Ta-/Ti-getter

quartz wool filter

oven(850 °C)

~10 m PFA-capillary

48Ca-Beam

recoil chamber

rotating 238U-target

(1.6 mg cm-2)

PIN-dioden oppositer

thermostat

surface

N2

(liq.)

(-196 °C)

(+35 °C)

a

S. SovernaJanuary 2004

Experiment GSI February-March 2003Experiment GSI February-March 2003238238U(U(4848Ca, 3n)Ca, 3n)283283112 (SF, 3min)112 (SF, 3min)

283112

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)

Current effort: focus on -decaying nuclides

V. Utyonkov, priv. comm. Feb. 2004

48Ca + 238U @ DGFRS/FLNR

Device 2004Device 2004Ar/He carrier gas loop (v=10 l)

Ar - refill

48Ca 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

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 ≥ 1019 required for approx. 1 month experiments: 1 pA average beam intensity! cw-LINAC; Novel target technology (stable compounds, liquid metal targets)

DGFRSDGFRS1 x

Ds179

sf 0.31 s

20 s8.7-8.9

114

EVR

290

20 s8.7-8.9

112283

5.4 s9.5

20 s8.7-8.9

114287

1.5 s10

244244Pu(Pu(4848Ca,5n)Ca,5n)287287114114

E* 52 MeV

242242Pu(Pu(4848Ca,3n)Ca,3n)287287114114

20 s8.7-8.9

114

EVR

290

Ds179

0.28 s9.7

20 s8.7-8.9

112283

7.8 s9.5

20 s8.7-8.9

Hs275

422 ms9.3

20 s8.7-8.9

sf

Sg271

6.3 m

20 s8.7-8.9

114287

1 s10

Ds179

sf 0.2 s

20 s8.7-8.9

114

EVR

290

20 s8.7-8.9

112283

4 s9.5

20 s8.7-8.9

114287

1 s10

16 x 1 x

E* 40 MeVE* 32-52 MeV

245245Cm(Cm(4848Ca,2n)Ca,2n)291291116116 20 s8.7-8.9

112283

8.57 s

20 s8.7-8.9

116

EVR

293

9.5

20 s8.7-8.9

116291

8 ms10.75

20 s8.7-8.9

114287

1 s10

Ds179

sf 0.2 s

2 x

E* 35 MeV

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 ≥ 1019 required for approx. 1 month experiments: 1 pA average beam intensity! cw-LINAC; Novel target technology (stable compounds, liquid metal targets)

220Rn

48Ca + 248CmH.W. Gäggeler et al., Phys. Rev. C33, 1983 (1986)

Transfer reaction products!Transfer reaction products!

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 ≥ 1019 required for approx. 1 month experiments: 1 pA average beam intensity! cw-LINAC;

- Novel target technology (stable compounds, liquid metal targets)

A recoil/gas chemistry chamber A recoil/gas chemistry chamber at the Berkeley Gas-filled at the Berkeley Gas-filled

Separator (BGS)Separator (BGS)

Hot-catcher coupled to vacuum thermochromatography set-up

Induction heating

SHE@CHEMSEP

HotCatcher

R. Eichler, Qin Zhi

75 80 85 90 95 100 105 110 115 120-200

0

200

400

600

800

1000

1200

Hsubl(Rh)

beginningrelease at1500°C

116

115

114

113

112

Ac

Th

Pa

UNp

PuAm

CfIII

Po

BiPb

Tl

Hg

MdEs

No

Cm

Fm

CfII

BkRhLr

actinides light elements, groups 12-16 transactinide elements

Re

lea

se

En

tha

lpy (

HR

h f), k

J/m

ol

Z

Hot Targets Hot Targets IntermetallicIntermetallic compounds with compounds with RhRh

R.Eichler, Qin Zhi

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 ≥ 1019 required for approx. 1 month experiments: 1 pA average beam intensity! cw-LINAC;

102 104 106 108 110 112 114 116-200

0

200

400

600

800

1000

1200

1400

1600H

0 A (

ve

rfl) U

,l (

kJ/m

ol)

Ordnungszahl ZA

Release enthalpy of transactinides from molten uranium

B. Eichler, PSI-03-01

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

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 ≥ 1019 required for approx. 1 month experiments: 1 pA average beam intensity! (cw-LINAC)