[email protected] - Institute for Nuclear Physics

Report
Latest results from MINIBALL at REX‐ISOLDE
• Overview physics case
• Last REX-ISOLDE campaign
• Perspectives with HIE-ISOLDE
Peter Reiter
IKP, University of Cologne
for the MINIBALL collaboration
3RD EGAN Workshop 24th – 27th June, 2013, University of Liverpool
Outline
- Physics case
- [email protected] - Perspectives
Shell Model Physics with [email protected]
“Island of inversion” N=20
Coulomb excitation &
transfer reactions
(Darmstadt, Cologne, Munich)
Phys. Lett. B, 700 ( 2011) 181
Phys. Rev. Lett. 105, 252501 (2010)
Phys. Rev. Lett. 103, 012501 (2009)
Phys. Rev. Lett. 94, 172501 (2005)
26,28,29,30Na
29,30,31,32Mg
Towards the doubly magic 78Ni
with Coulomb excitation and nucleon
transfer reactions around 68Ni
(CERN, Leuven, Munich)
66,67,68Ni
67,68,69,70,71,73Cu
72,74,76,78,79,80Zn
transfer reactions at N=28
(Darmstadt, Munich)
46Ar
Phys. Rev. C 84, 064323 (2011)
Phys. Rev. C 82, 064309 (2010)
Phys. Rev. C. 79, 014309 (2009)
Phys. Rev. Lett. 100, 112502 (2008)
Phys. Rev. C. 78, 047301 (2008)
Phys. Rev. Lett. 99, 142501 (2007)
Phys. Rev. Lett. 98, 122701 (2007)
Outline
- Physics case
- [email protected] - Perspectives
Shell Model Physics with [email protected]
Towards the doubly magic
(Lund, CERN)
100Sn
106,107,108,109,110Sn
107,108In
Phys. Rev. C 87, 017301 (2013)
Phys. Rev. C 86, 031302(R) (2012)
Eur. Phys. J. A (2012) 48: 105
Eur. Phys. J. A 44 (2010) 355
Phys. Rev. C 80, 054302 (2009)
Phys. Rev. Lett. 101, 012502 (2008)
Phys. Rev. Lett. 98, 172501 (2007)
100,102,104Cd
g-factors in Te isotopes
(Darmstadt, Madrid)
132,134,136Te
B(E2) measurements around
(Darmstadt, Munich)
122,123,124,128Cd
138,140,142,144Xe
140,142,148Ba
132Sn
Outline
- Physics case
- [email protected] - Perspectives
Shapes & collectivity with [email protected]
Shapes and collectivity
in the rare earth region
(Darmstadt, Saclay, Oslo)
138,140Nd
140,142Sm
142Gd
144Dy
Collectivity near Z=50
(York, Darmstadt)
116,118Te
Shapes and collectivity between Kr and Sr
(York, Cologne, Munich, Orsay,
Liverpool, Grenoble, Saclay)
72Kr
88,92,94,96Kr
93,95,97,99Rb
96Sr
Nucl. Phys. A 899 (2013) 1
Phys.Rev.Lett. 108, 062701 (2012)
Phys.Rev.Lett. 98, 072501 (2007)
Outline
- Physics case
- [email protected] - Perspectives
Shapes & collectivity with [email protected]
Shapes and collectivity
in light Po, Rn nuclei
(York, Jyväskylä)
206Po
202,204Rn
Octupole collectivity
in heavy Rn, Ra isotopes
(Liverpool)
220,222Rn
222,224Ra
Nature 497 (2013) 199
Shapes in Hg, Pb, Po nuclei
(Leuven, Liverpool, Jyväskylä)
182,184,186,188Hg
188,190,192,194,196,198Pb
196,198,200,202Po
Outline
-
Physics case
- [email protected] -
RIB Production:
• 1,4 GeV protons
• various targets
• ionization
• mass separation in GPS/HRS
• 800 RIBs available
New
• Astatine beam production
and ionization spectroscopy
• S. Rothe et al.,
Nat. Commun. 4:1835 doi:
10.1038/ncomms2819 (2013).
Island of Inversion - Perspectives
Outline
-
Physics case
- [email protected] -
Island of Inversion - Perspectives
Isomeric beams @ ISOLDE
• technique based on in-source laser spectroscopy
(Fedosseev, V. N. et al. Rev. Sci. Instrum. 83, 02A903 (2012))
• set the laser frequency to select and maximize the production of the
isomer of interest
668Cu
61+
722
0


70Cu
6- (g.s.)
31+
1+ 242
3- 101
60



1+ (g.s.)
g-Spectroscopy with Cu isomer beams: I. Stefanescu et al. PRL 98, 122701 (2007), E. Rapisarda et al. PRC 84, 064323 (2011)
• new case
123Sn
beam
T. Kroell et al., experiment IS524
Outline
-
Physics case
- [email protected] -
Island of Inversion - Perspectives
RIB preparation @ REX-ISOLDE
Re-acceleration
• acceleration of the ions in the
REX-LINAC
• beam energy: 0,8-3,0 MeV/u
Acceleration up to Ra achieved
Charge breeding:
• cooling and bunching of the
RIB in the REXTRAP
• breeding to higher charge
states in the EBIS to A/q<4.5
• breeding time up to 400 ms
• A/q selection
Outline
-
Physics case
- [email protected] -
Island of Inversion - Perspectives
MINIBALL
Coulomb excitation setup
segmented Si detector for particle
detection (DSSSD)
• 16 rings (front side)
• 96 strips (back side)
• angle coverage: θlab = 16-55°
• ΔE-E measurement possible (pad)
N. Warr, et al., Eur. Phys. J. A (2013) 49: 40
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
IS524 - Coulex of 123Cd

Cd ) ??
 ( h11 / 2 )  2 (
(9/2+)
Cd ) ???
xxx??
409
347
591
 (d 3/ 2 )  2 (
122
Physics aim:
374
250
(123)

122
S. Ilieva et a., to be published
Coupling of odd neutron to even core
 reveals which orbitals contribute to
collectivity
691
(5/2+,7/2+) 591
(9/2-) 440
116
(5/2+) 463
(5/2+,7/2+) 409
(1/2+) 116
3/2+
Enhanced quadrupole collectivity
observed in 122,124Cd (IS411)
11/2- 316
Additional finding from JYFLTRAP:
Level scheme needs major revision
as 11/2- isomer is not at 316 keV but
144(4) keV
A. Kankainen et al., Phys. Rev. C 87, 024307
0
H. Huck et al., PRC 40, 1384 (1989)
A.-L. Hartig, Th. Kröll, et al, TU Darmstadt
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
IS524 - Coulex of 123Cd
• First Coulex of odd Cd isotope
at REX-ISOLDE
• Beam intensity: ≈ 9 ·104/s
• Beam composition:
- 100% Cd
- RILIS beam
- ratio g.s./isomer varied by RILIS setting
(thanks to B. Marsh)
- ≈ 66% 123mCd and ≈ 33% 123Cd
Energy [keV]
Observables:
cross section ( B(E2)’s), g -ray angular distributions ( spin/parity), ...
First results:
• New transition observed: 463 keV, ...
• Branchings and intensities are not consistent with level scheme in literature
Analysis by Anna-Lena Hartig (MSc project) [Th. Kröll, S. Ilieva, S. Bönig, M. Thürauf, M. Scheck]
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
Oblate shape in 72Kr
- a rarity that gives a deeper understanding of effective nucleon-nucleon interaction
Spokesperson: B.S. Nara Singh, IS478, proposed in 2007
104Pd
72Kr
2 mg/cm2
at 200 MeV
CD+PAD
Considerable efforts over 5 years
– beam development and several
attempts
~150 counts in
710 keV line
May 2012
~ 28 % effect
http://npg.york.ac.uk/structure_current.html
B.S. Nara Singh, U of York for the IS478 collaboration
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
Shape transition and coexistence in
neutron-deficient rare earth nuclei:
Coulomb excitation of 140Sm
A.Görgen et al. Univ. Oslo
ISOLDE IS495 (July 2012)
beam
 140Sm @ 2.85 A MeV
 RILIS
 2105 pps @ Miniball
ground-state deformation
Gogny HFB
Prolate
Oblate
configuration mixing caclculation
J.-P. Delaroche et al.
Phys. Rev. C 81, 014303 (2010)
target
 94Mo, 2 mg/cm2

Qs
94
B(E2)
(0+)
Qs
B(E2)
2+
0+

21  01
4+
Doppler correction projectile
Doppler correction target
Mo
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
IS495: Differential cross sections – GOSIA analysis
preliminary
63    cm  71 
71    cm  82 
82    cm  95 
95    cm  113 
M.Klintefjord, et al., Univ. Oslo
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
Mixed symmetry states in N=80 isotones
Present situation & Predictions
QPM, IBM
Shell model
Single 2+ MSS of 132Te, 134Xe, 136Ba
Fragmented 2+ MSS of 138Ce
QPM and SM reproduce situation in N=80
What is the predictive power?
• QPM: single 2+ MSS of 140Nd
• SM: fragmented 2+ MSS of 140Nd
Identify and quantitatively study
MSSs of 140Nd and 142Sm
C. Bauer, N. Pietralla, et al, TU Darmstadt
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
140Nd,142Sm
– MINIBALL
140Sm
142Sm
140Nd
142Sm
140Nd
result
C. Bauer, et al., Phys. Rev. C in press
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
Results: new B(E2) values
N=80 Isotone: 140Nd and 142Sm
40
82
82
1h11/2
3s1/2
2d3/2
B(E2) [W.u.]
30
2d5/2
1g7/2
50
50

35
p
Exp. data
New measurement
QPM
LSSM
25
20
15
10
5
0
50
52
54
56
58
Proton number Z
comparison with
• quasi-particle phonon calculations (N. Lo Iudice et al., PRC 77, 044310 (2008))
• large-scale shell model calculations (D. Bianco et al., PRC 85, 034332 (2012))
60
62
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
Shape
coexistence
Generalized
seniority
Change in nuclear structure in
neutron deficient Po isotopes
(π1h9/2)2
N = 116
Laser spectroscopy at ISOLDE
T.E. Cocolios et al. PRL 106:052503 (2011)
Transition expected around 200Po
A.M. Oros et al NPA 645:107 (1999)
R. Julin et al JPG 27:R109 (2001)
N. Kesteloot, et al., Univ. of Leuven
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
N. Kesteloot, et al., Univ. of Leuven
Coulomb excitation 196,198,200,202Po
196Po
463 keV
2+0+ 196Po
556 keV
2+0+ 104Pd
200Po
666 keV
2+0+ 200Po
605 keV
2+0+ 198Po
198Po
871 keV
2+0+ 94Mo
202Po
677 keV
2+0+ 202Po
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
224Ra
(+120Sn) Coulomb excitation
-Heaviest
REX-ISOLDE beam
- B(E3, 0+ ↦ 3-)
L.P. Gaffney, P. A. Butler, M. Scheck, A. B. Hayes, F. Wenander, et al.,
Nature 497, 199-204 (2013) doi:10.1038/nature12073
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
Permanent EDM violates
both T & P symmetries
Atomic EDM moment
‘For a NR system made up of point, charged particles which interact electro-statically
with each other and with an arbitrary external field, the shielding is complete.’
L.I. Schiff, Phys. Rev. 132 (1963) 2194
Theoreticians search for loopholes in:
• relativistic effects (electron)
• finite-size effects of nucleus can break the symmetry (nucleus)
• magnetic interactions (electron–nucleus)
• non-EM exotica in electron-nucleon interaction
Nuclear pear-shapes can enhance the “Schiff moment” by ~ 3 orders of magnitude
Search candidates are odd-A Rn (TRIUMF) and Ra (ANL, ISOLDE)
Outline - Physics case - [email protected] - Coulomb excitation - Perspectives
221Rn
Results so far
Kα1, Kα2
↓
221Rn,
6x103 ion/s
30 hour beam time
120Sn target, 2 mg/cm2
223.5 keV
22.5 keV
7/2+, 0 keV
Kβ1
↓
223.5
↓
201.0
↓
289.3
↓
George O’Neill, et al., University of Liverpool
Outline - Physics case - [email protected] -
Perspectives
SPEDE - SPectrometer for Electron DEtection
Si detector in backwards geometry
Allows conversion electron spectroscopy – complete picture
Outline
-
Physics case
- [email protected]
- Perspectives
The MINIBALL T-REX setup
T-REX: Si detector array for Transfer experiments at REX-ISOLDE
• large solid angle (58% of 4π)
• position sensitive
• PID (ΔE-E): p, d, t, α,
… and e- from β-decay (!)
Technical details:
Barrel: 140 mm ΔE / 16 resistive strips
1000 mm E / pad
Backward CD: 500 mm ΔE / DSSSD
500 mm E / pad
RIB
V. Bildstein, K. Wimmer,
Th. Kröll, R. Gernhäuser et al.
(funded by TU München,
KU Leuven, U Edinburgh, CSNSM
Orsay, TU Darmstadt)
Outline - Physics case - [email protected] - Transfer reaction - Perspectives
d(66Ni,67Ni)p – the 68Ni region (N=40)
J. Diriken, P. van Duppen, R. Raabe, et al.; IKS-KU Leuven for the IS469 collaboration
Outline - Physics case - [email protected] - Transfer reaction - Perspectives
d(66Ni,67Ni)p – the 68Ni region (N=40)
• proton gated g-spectrum
• g-transitions up to 5800 keV
• p-g-g coincidence analysis
• p-gprompt -gdelayed analysis
High resolution of MINIBALL allows to resolve
states and to analyse angular distribution
J. Diriken, et al.; PRL submitted
Outline - Physics case - [email protected] - Transfer reaction - Perspectives
d(66Ni,67Ni)p – the 68Ni region (N=40)
-1
p1/2
g9/2
d5/2
Partial level scheme,17 levels identified and characterized
J. Diriken, et al.; PRL submitted
d5/2
S. Bottoni, S. Leoni, et al.;
INFN -,Uni. Milano
for the IS536 collaboration
Outline - Physics case - [email protected] - Island of Inversion
- Perspectives
HIE-ISOLDE
• intensity upgrade
• energy upgrade
1.2
MeV/u
3
MeV/u
5.5
MeV/u
2015
8
MeV/u
10
MeV/u
2016
Outline
-
Physics case
-
[email protected] - Island of Inversion - Perspectives
Summary
• REX-ISOLDE versatile accelerator
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• MINIBALL physics case covers
nuclei up to Radium
- Coulex with isomeric and heavy beams
- transfer reactions & g-ray spectroscopy
• Major perspective: HIE-ISOLDE
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• First years: Shell model physics
• Recent developments:
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