ds and its decay productstan11.jinr.ru/pdf/08_sep/s_2/03_ackermann.pdf30 35 40 45 50 12.7.2004),2 ,2...
TRANSCRIPT
Dieter Ackermann Sochi, September 8th 2011
270Ds and Its Decay Products
– Decay Properties and Experimental Masses
Dieter Ackermann
GSI Helmholtzzentrum für Schwerionenforschung GmbH
Sochi, September 8th 2011
Dieter Ackermann Sochi, September 8th 2011
Nuclear Structure Studies at SHIP - Status Overview
discoverd at SHIP
new or improved decay data
or X-rays measured
new isomeric states discovered
outline • decay spectroscopy @ SHIP
• K-isomers – two examples (252,254No)
• new results for 270Ds from second experiment in 2010
Dieter Ackermann Sochi, September 8th 2011
• isomer surviving separation
• emission after decay
• CE for highly converted transitions + X-ray emission
emission
emission
CE emission
emission
evaporation residue after separation
x-ray emission
Nuclear Structure of SHE - Decay Spectroscopy at SHIP/TASCA
Dieter Ackermann Sochi, September 8th 2011
high eff.
15%
(e.g. SHIP,
TASCA...)
• inclusive measurement • ER, 's, 's and e-
• clean • particle discrimination • ER- - correlations
• highly efficient • close geometry • stopped source
40 60 80 100 120 140 160 180 200 220 240 260 280 300 320
0
5
10
15
20
25
30
35
40
45
50
12.7.2004
(86,2
+-
0,3
)
143,3
+-
0,2
203,6
+-
0,2
co
un
ts
E / keV
- spectrum
in coincidence
to 255Rf -decay
F.P. Heßberger et al, EPJ A 30, 561 (2006)
Nuclear Structure of SHE - Decay Spectroscopy at SHIP/TASCA
Dieter Ackermann Sochi, September 8th 2011
184
162
126
152
neutrons protons
82
114
100 102
142
134 96
108
Nuclear Structure of Heavy Nuclei - Single Particle Levels and Deformation
Dieter Ackermann Sochi, September 8th 2011
184
162
126
152
neutrons protons
82
114
100 102
96 142
134
108
9/2-[734]
j15/2
d5/2
1/2+[631]
7/2-[514]
h9/2
f5/2
1/2-[521]
f7/2
7/2+[633]
i13/2 3/2-[521]
g9/2
7/2+[624]
Nuclear Structure of Heavy Nuclei - Single Particle Levels and Deformation
Dieter Ackermann Sochi, September 8th 2011
Nuclear Structure of the Heaviest Nuclei: - Production Rates
reaction σ/nbarn Ibeam/pμA countrate . 208Pb(48Ca,2n)254No 2000 1 15000 /h (at RITU/Jyväskylä 200 /h) 206Pb(48Ca,2n)252No 430 1 3300 /h 206Pb(48Ca,3n)251No 25 1 200 /h 209Bi(40Ar,2n)247Md 7 3 80 /h 208Pb(54Cr,1n)261Sg 2 1 15 /h 207Pb(64Ni,1n)270Ds 0.013 0.5 1 /d
Dieter Ackermann Sochi, September 8th 2011
13 cases: even-even: 10 even-odd: 2 odd-even: 1 Sg and Hs isotopes? T1/2: 70 ns (256Fm) – 1.92 s (250Fm) E*: 1-1.5 MeV (2.5 MeV for 254m2No)
270mDs T= ms
270g.s.Ds T= s
2.8
2.20.6140
40100
K-isomers for Z = 96 - 110 - Experimental Information
Dieter Ackermann Sochi, September 8th 2011
0 100 200 300 400 5000
50
100
150
200
Co
un
ts
t (ms)
T1/2
=101.2 ± 13.9 ms
206Pb(48Ca,2n)252No
0 50 100 150 200 700 750 800 850 900 950
0
50
100
150
200
250
No252iso
F.P.Heßberger 8.6.2006
K (
+ 1
23 ?
)
156
133
687
107 (
4+
-->
2+
) (lin
e d
uble
tt)
167 (
6+
-->
4+
)
224 (
8+
-->
6+
)
(evtl. diff. lifetim
e)
710
828
862
882
911
920
Co
un
ts
E / keVB. Sulignano et al. EPJ A33, 327 (2007)
B. Sulignano, PHD thesis, Universität Mainz, 2007
Nuclear Structure of the Heaviest Nuclei: - Isomeric states: 252No
Dieter Ackermann Sochi, September 8th 2011
208Pb(48Ca,2n)254No
25 50 75 100 125 150 175 200 225 250
0
20
40
60
80
250 275 300 325 350 375 400 425 450 475 500
0
5
10
15
20
25
500 525 550 575 600 625 650 675 700 725 750
0
10
20
30
40
50
60
No254m2_clo_einzel_r229_r2479.5.2007
E / keV
Ere
ign
isse
Ere
ign
isse
179.5
Ere
ign
isse
168.5
156.9
111.4
147.5
143.6
133.3
347.1
325.5
311.9
301.8
605.7
R.D. Herzberg et al.,
Nature 442, 896 (2006);
S.K. Tandel et al.,
Phys. Rev. Lett. 97, 082502 (2006)
F.P. Heßberger et al.,
Eur. Phys. J. A 43, 55-66 (2010)
Nuclear Structure of the Heaviest Nuclei: - Isomeric states: 254No
Dieter Ackermann Sochi, September 8th 2011
270Ds 266Hs (6 chains) chain# 1, 3 and 5 chain# 2
chain# 8 chain# 7
Theory:
rotational levels: A. Sobiczewski et al.
K-isomers S. Cwiok et al.
Experiment:
S. Hofmann et al.
266Hs 262Sg (8 chains) chain# 1-8 262Sg decay (8 chains)
chain# 1-8
8+
6+
270Ds and its Decay Products - 1st experiment in 2000 (S. Hofmann et al., Eur. Phys. J. A 10, 5 (2001)
Dieter Ackermann Sochi, September 8th 2011
162
[725]11/2-
[615]9/2+
[613]7/2+
1.34 MeV I = 10-
162
[725]11/2-
[615]9/2+
[613]7/2+
1.31 MeV I = 9-
neutrons
162
[725]11/2-
[615]9/2+
[613]7/2+
g.s.
Fermi
level
S. Cwiok, et al. HFB 2
117252
7613
270Ds: Z=110 N= 160
211725
29615
K-isomer in 270Ds - Theory Predictions: quasi particle excitation
Dieter Ackermann Sochi, September 8th 2011
-3 -2 -1 0 1 2 3
72
74
76
78
80
82
84
86
88
90
92
Me
an
tim
e o
f fli
gh
t /
s
Excitation frequency / Hz - 850012
253No
2+
-200
-150
-100
-50
0
50
253No252
No
MS
HIP
TR
AP-M
AM
E / k
eV
SHIPTRAP
AME'03
254No
SHIPTRAP August 2008
?
Decay Chain of 270Ds from 64Ni+207Pb - Results from October 2000 and Possible Extension
Dieter Ackermann Sochi, September 8th 2011
Observed types of decay chains I - ER-α-α-sf
a) ER-α-α-sf
15 chains
Dieter Ackermann Sochi, September 8th 2011
270Ds - 270Ds α-decay
• 26 decay chains (270Ds: 25, 271Ds:1)
• new spectroscopic data
* T1/2 from S. Hofmann et al., Eur. Phys. J. A 10, 5 (2001)
*
Dieter Ackermann Sochi, September 8th 2011
Observed types of decay chains II - ER-α-sf
a) ER-α-α-sf b) ER-α-sf
15 chains 8 chains
sf(266Hs) = 32%
Dieter Ackermann Sochi, September 8th 2011
270Ds - 266Hs sf-branch
new fission branch
in 266Hs
• 26 decay chains (270Ds: 25, 271Ds:1)
• new spectroscopic data
* T1/2 from S. Hofmann et al., Eur. Phys. J. A 10, 5 (2001)
*
*
Dieter Ackermann Sochi, September 8th 2011
Observed types of decay chains III - ER-α-α-α-sf
a) ER-α-α-sf b) ER-α-sf c) ER-α-α-α-sf
15 chains 8 chains
sf(266Hs) = 32%
2 chains
α(262Sg) = 8%
Dieter Ackermann Sochi, September 8th 2011
270Ds - News III – 262Sg α-branch link to 254No
• 26 decay chains (270Ds: 25, 271Ds:1)
• new spectroscopic data
80
90
100
110
120
130
140
102 104 106 108 110
-1
0
1
2
270Ds
266Hs
262Sg
258Rf
254No
mc
2 /
Me
V
Möller-Nix
Liran-Zeldes
Myers-Swiatecki
Smolanczuk-Sobiczewski
Atomic Number
(m
c2(e
xp
)-
mc
2(t
heo
)) /
MeV
new fission branch
in 266Hs
α-decay link 262Sg 258Rf
* T1/2 from S. Hofmann et al., Eur. Phys. J. A 10, 5 (2001)
*
*
*
J. M. GATES et al. PRC 77, 034603 (2008)
Dieter Ackermann Sochi, September 8th 2011
0,01 0,1 1 10 100
270Ds
266Hs
262Sg
Experiment 2000
Experiment 2010
270m
Ds ms
270gs
Ds ms
266
Hs ms
266
Hs ms
266
Hs ms
262
Rf ms
262
Sg ms
decay time [ms]
258Rf
0,01 0,1 1 10 100
270Ds
266Hs
262Sg
Experiment 2000
Experiment 2010
270m
Ds ms
270gs
Ds ms
266
Hs ms
266
Hs ms
266
Hs ms
262
Rf ms
262
Sg ms
decay time [ms]
258Rf
Decay details
- time distributions
Run 197 - experiment 2000 Run282 - experiment 2010
105 ms
Decay chain 8
266
Hs
270
Ds
262
Sg
271
Ds
10.968 MeV
5.31 ms
180 MeV + ?
6,239 ms
10.440 MeV
104,66 ms
Dieter Ackermann Sochi, September 8th 2011
270Ds Decay Scheme
270Ds:
13 g.s. decays - 2 γ‘s: 175/741 keV 12 isomer decays - 1 γ: 1094 keV (in 2000: 3:3 + 1 γ)
chain 8: Eα 200-300 keV lower
266Hs: 16 g.s. decays 1 isomer decay with a 332 keV γ-ray
chain 8: Eα 200 keV higher Ev = 332 keV
262Sg: α decay observed for the first time (1 full E, 1 escape)
332 kev
Calculations: HFB: S. Cwiok, et al. PES: F.R. Xu, et al. PRL 92, 252501 (2004) TCSM: G.G. Adamian et al., PRC 81, 024320 (2010)
8+
9-
10-
10+ 9-
8+
9- 10-
10+ 8+
6+ 7- 4- 9-
9-
10- 10-
6- 8+
6+ 10-
9-
10- 8+ 6+
7-
9- 10-
7- 6+ 4+ 5+ 5-
Dieter Ackermann Sochi, September 8th 2011
ground state, decay and structure properties up to Z=110 • α-γ coincidences (total: 4)
• fission branch in 266Hs
• experimental mass for 270Ds
• new K-isomer 266 Hs
Summary - Achievements
Dieter Ackermann Sochi, September 8th 2011
• nuclear structure studies single particle states/level density gap
• reaction mechanism systematics (transfer, fission, incomplete fusion, spin distribution, ...)
• efficiency upgrade DC accelerator
• mass measurement Ebind
• mass determination (A(Z) identification) new separator/spectrometer
• employment of all available technology and methods (ER-α-γ correlations, chemistry, traps, mass determination, ...)
“rare isotopes”? yes for systematic investigations maybe(???) for SHE synthesis (low beam intensity!!!)
localisation of the region of spherical shell-stabilized SHE
beam
beam separator
(e.g. velocity filter)
M/q spectrometer
particle and phonon
detection array
• efficient beam separation • high transmission • M/q separation • highly efficient particle and photon detection
New M/q spectrometer – separator for SHE
target Possible Solution:
S3
@
SHE Synthesis and Nuclear Structure of SHE - Roadmap/Long Term
Possible GSI
acc. schemes:
HSI IH Stripper CH
SIS 18
HSI IH Stripper CH
SIS 18
HSI IH Stripper CH
SIS 18
HSI IH Stripper CH
SIS 18
HSI IH Stripper CH
SIS 18
high charge cw-injector
high charge cw-injector
material science/ISL
SHIP
TASCA X1
SHIP
TASCA X1
ISL
HSI
HSI
cw
warm
cw cold
UNILAC
SIS ECR 1
ECR 2 MUCIS
MEVVA
Penning
SHE Exp.
Dieter Ackermann Sochi, September 8th 2011
D.A., M. Block, H.G. Burkhard, Ch. Dröse, M. Dworschak, F.P. Heßberger, S. Hofmann, W. Hartmann, A. Hübner,
B. Kindler, J. Khuyagbaatar*, I. Kojouharov, B. Lommel, R. Mann, J. Maurer, E. Minaya, J. Steiner, B. Sulignano** Gesellschaft für Schwerionenforschung (GSI)
D-64220 Darmstadt, Germany
A.G. Popeko, A.V. Yeremin Flerov Laboratory of Nuclear Reactions, JINR
Ru-141 980 Dubna, Russia
S. Antalic, S. Šaro, M. Venhart Department of Nuclear Physics,
Comenius University
SK-84248 Bratislava, Slovakia
M. Leino, J. Uusitalo Department of Physics, University of Jyväskylä
FIN-40351 Jyväskylä, Finland
V.F. Comas, J.A. Heredia Higher Inst. of Technologies and Appl. Sciences Havana 10600, Cuba
K. Nishio Japan Atomic Energy Research Institute
Tokai, Ibaraki 319-1195, Japan
R. Dressler Paul-Scherrer Institute (PSI)
5232 Villigen, Switzerland
* also university of St. Petersburg, Russia ** now CEA Saclay, France
The SHIP Collaboration
photograph by Gabi Otto
Dieter Ackermann Sochi, September 8th 2011
Dieter Ackermann Sochi, September 8th 2011
The ECOS Network Activity in the ENSAR framework of the EU FP7 program has among others with its Task 2 the objective to promote synergies in the field of Super-Heavy Element (SHE) research, described as follows: "For this task ECOS is aiming for bringing together the groups with research activities on SHE using high-intensity ion beams for an exchange of new ideas and techniques related to the use of very high intensity stable beams. In particular, Task 2 will propose an optimisation of resources (beam time, target technology, detectors) in the field of SHE research among TNA facilities." The ENSAR-ECOS Workshop on FUture Super-Heavy Element Strategy – FUSHE 2012 is one very important milestone in this process. It will provide a forum for the SHE community to discuss and define the future strategy to reach the common goal – the establishment and investigation of the region of spherical shell-stabilised super-heavy nuclei – the so called “Island of Stability”.
Dieter Ackermann Sochi, September 8th 2011
FUSHE 2012 - Venue
The Conference&Sports Hotel Erbismühle is located in a nice valley, the Weiltal, in the Taunus hills about 50 km north of Frankfurt (50 km to Frankfurt main station and 55 km to Frankfurt airport) close to the village Weilrod in the centre of Germany. 72 rooms €90 (€60 double occupation) + interesting food option The Taunus hills have formed the northern border of the Roman Empire and traces of it can still be visited today like the rebuilt Roman Castle Saalburg together with a few meters of the limes, the Roman border installations and defence line against the barbarians north of it…
Dieter Ackermann Sochi, September 8th 2011
FUSHE 2012 - Contact
Dieter Ackermann (Chair): [email protected] David Boilley (Co-chair): [email protected] Christelle Stodel (Scientific secretary): [email protected] Secretaries: Ms. Siglind Raiß: [email protected] Tel.: +49-6159-71-2412 Ms. Tatjana Litvinova: [email protected] Tel.: +49-6159-71-2127 Fax: +49-6159-71-2902.
Workshop email address: [email protected] Webpage: http://www.ensarfp7.eu/workshops/fushe2012/