The Superheavy Element Programme at TASCA @ GSI/FAIR · Chemistry A. Yakushev et al., Inorg. Chem,...
Transcript of The Superheavy Element Programme at TASCA @ GSI/FAIR · Chemistry A. Yakushev et al., Inorg. Chem,...
The Superheavy Element Programme at TASCA @ GSI/FAIR
Ulrika Forsberg on behalf of the TASCA collaboration
September 29, 2016NUSTAR Week, York
Superheavy elements
new sub-collaboration in
NUSTAR@FAIR
Outline
• Superheavy elements (SHE)
• The TASCA separator
• Experiments and main results
• Plans for the future
Periodic table
104Rf
105Db
106Sg
107Bh
108Hs
109Mt
110Ds
111Rg
112Cp
113Uut
114Fl
115Uup
116Lv
117Uus
118Uuo
Superheavy elements: Z ≥ 104
100
120
114
162
184
108
152
Cn
N
Z
DsMt
HsBh
a
b +
EC
SF
b-
Rg
172 Mic-Mac (A. Sobiczewski)
RMF (Zhang)
113
117118
Lv115
Fl
Courtesy of Ch.E. Düllmann 5
Superheavy Elements: Z ≥ 104
S.G. Nilsson
et al.(1969)
100
120
114
162
184
108
152
Cn
N
Z
DsMt
HsBh
a
b +
EC
SF
b-
Rg
172 Mic-Mac (A. Sobiczewski)
RMF (Zhang)
113
117118
Lv115
Fl
6
Superheavy Elements
Courtesy of Ch.E. Düllmann
1 atom s-1
1 atom d-1
100
120
114
162
184
108
152
Cn
N
Z
DsMt
HsBh
a
b +
EC
SF
b-
Rg
172 Mic-Mac (A. Sobiczewski)
RMF (Zhang)
113
117118
Lv115
Fl
7
Mass measurements M. Block et al., Nature 463 (2010) 785
E. Minaya Ramirez et al., Science 337 (2012) 1207
ChemistryA. Yakushev et al., Inorg. Chem,
Nuclear structure and X-raysD. Rudolph et al., PRL 111 (2013) 112502
Laser spectroscopyM. Laatiaoui et al., to be published
Superheavy Elements – Highlights from the past years
Courtesy of Ch.E. Düllmann
Elements confirmedJ. Khuyagbaatar et al., PRL 112 (2014) 172501
S. Hofmann et al., EPJA 48 (2012) 62
New element searchesCh. E. Düllmann et al., in preparation
100
120
114
162
184
108
152
Cn
N
Z
DsMt
HsBh
a
b +
EC
SF
b-
Rg
172 Mic-Mac (A. Sobiczewski)
RMF (Zhang)
113
117118
Lv115
Fl
8
Superheavy Elements
Courtesy of Ch.E. Düllmann
Courtesy of Ch.E. Düllmann
The TASCA Collaboration
10Courtesy of Ch.E. Düllmann
LBNL/UCB Berkeley (USA) U Jyväskylä (Finland)
LLNL Livermore (USA) U Oslo (Norway)
Vanderbilt U (USA) Chalmers U Gothenburg (Sweden)
ORNL Oak Ridge (USA) PSI Villigen/U Berne (Switzerland)
U Liverpool (UK) ITE Warschau (Poland)
U Surrey (UK) U Lund (Sweden)
SINP Kolkata (India) IIT Roorkee (India)
IMP Lanzhou (China) ANU Canberra (Australia)
RIKEN Wako (Japan) JAEA Tokai (Japan)
TASCA
Beam
TargetDipole
Q1Q2
Search for element 120
Fl
113
117
118
Lv
115
119
120
102 104 106 108 110 112 114 116 118 120
1E-15
1E-14
1E-13
1E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6 Projectile Target48
Ca,...,70
Zn + 208
Pb/209
Bi13
C,...,26
Mg + 238
U...249
Bk48
Ca + 238
U,...,249
Cf
cro
ss
sec
tio
n /
ba
rn
atomic number Z
Synthesis of superheavy elements
Warm fusion
(48Ca + actinides)
13Courtesy of Ch.E. Düllmann
249Cf: heaviest
target 48Ca-era ends 20
98
How to synthesize element 120?
14
249Cf + 50Ti 299120
Courtesy of Ch.E. Düllmann
15Courtesy of Ch.E. Düllmann
Target Chamber
side view
DSSSD State-of-the-Art Stop Detector Array
48 mm
144 mm
6900 pixels
Electronics
Analogue electronics + digital electronicsFEBEX
Developed at GSI-EE
60 MHz dead-time free ADC sampling
www.gsi.de
Electronics
Analogue electronics + digital electronicsFEBEX
time (16.7ns/channel)
Sig
nal he
ight (a
rb. units)
α1
α2 FEBEX:
Can resolve events
separated by ~100 ns.
Fast decays from E120 can be measured
Two fast α decays of ~5 MeV cannot be confused with one α decay of ~10 MeV.
102 104 106 108 110 112 114 116 118 120
1E-15
1E-14
1E-13
1E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6 Projectile Target48
Ca,...,70
Zn + 208
Pb/209
Bi13
C,...,26
Mg + 238
U...249
Bk48
Ca + 238
U,...,249
Cf
cro
ss
sec
tio
n /
ba
rn
atomic number Z
TASCA Search for element 120 in 50Ti + 249Cf reaction
2011:
Z=12050Ti + 249Cf
39 d200 fb
18Courtesy of Ch.E. Düllmann
Search for E119
Reaction: 50Ti + 249Bk → 299-x119 + xn22 97
Fl
113
117
118
Lv
115
120
119
249Cf 98
Production and separation: Target production:
102 104 106 108 110 112 114 116 118 120
1E-15
1E-14
1E-13
1E-12
1E-11
1E-10
1E-9
1E-8
1E-7
1E-6 Projectile Target48
Ca,...,70
Zn + 208
Pb/209
Bi13
C,...,26
Mg + 238
U...249
Bk48
Ca + 238
U,...,249
Cf
cro
ss
sec
tio
n /
ba
rn
atomic number Z
Cross Sections in Hot / Cold / 48Ca Induced Fusion Reactions
Z=11950Ti + 249Bk
70 fb
20Courtesy of Ch.E. Düllmann
E117 confirmation
Reaction: 48Ca + 249Bk → 297-x117 + xn20 97
Fl
113
117
118
Lv
115
120
119
Element 117 among Top Ten Physics News Stories in 2014
Every year, APS selects Top Ten PhysicsNews Stories, which received largestpublic attention. The 2014 list includeshighlights like
•intergalactic neutrinos from IceCube,
•Rosetta/Philae comet mission
•blue LEDs (physics nobel prize 2014)
•our Element 117
•...
J. Khuyagbaatar et al., Phys. Rev. Lett. 112 (2014) 172501
22Courtesy of Ch.E. Düllmann
E114 & E113 Chemistry
Fl
113
117
118
Lv
115
120
119
Courtesy of Ch.E. Düllmann
Ge cluster
E115 trajectory
243Am target
E114 & E113 Chemistry
COMPACT
A. Yakushev
E114 & E113 Chemistry
A. Yakushev et al., Inorg. Chem. 53, 1624 (2014)
Results from first E114 exp: … and subsequent exp:
Stay tuned!
E115 Fingerprinting 48Ca-induced reactions give chains that
end by spontaneous fission
Courtesy of Ch. E. Düllmann
Superheavy elements, Z ≥ 104
Need direct measurement of atomic numbers!
Yu.Ts.Oganessian, J. Phys.G34, R165 (2007) etc.
Fl
113
117
118
Lv
115
120
119
→ X-rays
α
γ-rays orinternal conversions
100-500keV
Look for characteristic X-rays emitted in coincidence with α decays!
E115 Fingerprinting
Energy depends on proton number!
TASCA
CLUSTER
CLOVER
CLOVER
CLOVER
CLOVER
L.-L. Andersson et al., NIM A622, 164 (2010)
10.42(1) MeV0.437 s
268Db
272Bh
276Mt
280Rg
284113
288115
9.96(1) MeV0.965 s
9.75(1) MeV11.4 s
9.87(1) MeV 1.69 s
9.07(1) MeV4.05 s
161 MeV134.4 h
10.34(1) MeV1.46 s
281Rg
285113
289115
9.89(1) MeV0.0262 s
220 MeV0.432 s
10.64(5) MeV 0.0676 s
267Db
271Bh
275Mt
279Rg
283113
287115
10.23(1) MeV0.0684 s
1.33(1) MeV0.0161 s
10.33(1) MeV 0.0513 s
8.76(5) MeV 2.60 s
191 MeV30.6 min
4n
2n
3n
1 22 7 short
= detected in beam off period
?
Experiment30 chains detected in 18 days
3n ?
10.42(1) MeV0.437 s
268Db
272Bh
276Mt
280Rg
284113
288115
9.96(1) MeV0.965 s
9.75(1) MeV11.4 s
9.87(1) MeV 1.69 s
9.07(1) MeV4.05 s
161 MeV134.4 h
10.34(1) MeV1.46 s
281Rg
285113
289115
9.89(1) MeV0.0262 s
220 MeV0.432 s
10.64(5) MeV 0.0676 s
267Db
271Bh
275Mt
279Rg
283113
287115
10.23(1) MeV0.0684 s
1.33(1) MeV0.0161 s
10.33(1) MeV 0.0513 s
8.76(5) MeV 2.60 s
191 MeV30.6 min
4n
2n
3n
1 22 7 short
= detected in beam off period
?
Experiment30 chains detected in 18 days
3n ?
288115α1
284113
280Rg
α2
276Mt109
272Bh107
111
268Db105
α3
α4
α5
10.29(1) MeV 0.366 s
9.24(1) MeV 0.935 s
9.77(1) MeV11.1 s
0.825(3) MeV (escape) 0.515 s
9.06(1) MeV 15.3 s
FISSION, 197 MeV, 17.4 hours, 4 γ
Photons: 136(1), 167(1) keV
ExperimentPotential X-rays
Kα2 Kβ Bh (Z=107)
Difference between neighbouring Z: 3-4 keV
Accurate to 0.5%T.A. Carlson et al., Nucl. Phys. A 135, 57 (1969)
Experiment
Special thanks to …
111, 112502 (2013)
ENSARUNILAC
… among the Top Ten APS Physics Newsmakers of 2013!
E115 is everywhere…
10.42(1) MeV0.437 s
268Db
272Bh
276Mt
280Rg
284113
288115
9.96(1) MeV0.965 s
9.75(1) MeV11.4 s
9.87(1) MeV 1.69 s
9.07(1) MeV4.05 s
161 MeV134.4 h
10.34(1) MeV1.46 s
281Rg
285113
289115
9.89(1) MeV0.0262 s
220 MeV0.432 s
10.64(5) MeV 0.0676 s
267Db
271Bh
275Mt
279Rg
283113
287115
10.23(1) MeV0.0684 s
1.33(1) MeV0.0161 s
10.33(1) MeV 0.0513 s
8.76(5) MeV 2.60 s
191 MeV30.6 min
4n
2n
3n
1 22 7 short
= detected in beam off period
?
Experiment30 chains detected in 18 days
3n ?
TASC
AB
GS
Du
bn
a10
4
115
113
Rg
115
113
E3,t3
E2,t2
E1,t1
E1,t1
E2,t2
U. Forsberg et al., NPA (2016)
TASC
AB
GS
Du
bn
a10
4
115
113
Rg
115
113
E3,t3
E2,t2
E1,t1
E1,t1
E2,t2
NOT a set of chains following the same decay path! (<1% error risk)
E115-E117
289115
285113
281Rg
293117
289115
281Rg
285113
0.32( ) s
1.7( ) s
7( ) s
0.25( ) s
2.7( ) s
18( ) s
127
64
3
11
2
6
47
612
16
14
”Cross bombardment”:same isotope seen in different reactions
NOT a set of chains following the same decay path! (<<1% error risk)
Open for public review until November 8 2016
ExperimentFuture
Since UNILAC is not suited for simultaneousacceleration of beams for SIS100 and SHE research…
ExperimentFuture
New dedicated sc cw LINAC is planned!
Energy: 3.5-7.5 MeV/u
Uncertainty: <3 keV/u
Duty cycle: 100%
Length: 13.5 m
ExperimentFuture
W. Barth et al. Proc. IPAC 2013
Step 1: Build demonstrator unit
ExperimentFuture
Nov. 19, 2015: Delivery of cryostat to GSI
ExperimentFuture
ExperimentFuture
Superheavy element research:• new elements• nuclear spectroscopy• laser spectroscopy• X-ray fingerprinting• chemistry• mass measurements• …