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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on actinide targetsreactions on actinide targets(FLNR, published and(FLNR, published andunpublished data)unpublished data)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)