Nuclear Structure of the Doubly Magic 100Snand its Neighbors
Decay Spectroscopy at EURICA

Roman Gernhäuser, TU-München

introduction
isotope production
EURICA@RIBF
selected results
expected results

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Motivation
N=Z
super allowed Fermi decay
super allowed GT decay
isobaric analogue statesand pn interaction
rp – process
proton drip line
bp and p – decay
t1/2 and branching ratios

D. Bazin et al., Phys. Rev. Lett. 101, 252501 (2008)
C.B. Hinke et at., Nature 486, 341–345, (2012) , and many others!
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Rising at GSISuperallowed Gamow–Teller decay of thedoubly magic nucleus 100Sn
Ch. Hinke et at., Nature 486, 341–345, June 2012

Decay gspectrumof 100Sn

244 100Snnuclei
identified
s = 5.8 (21)pb

superallowed

log(ft) = 2.62 +0.13−0.11

GT
100Sn

BGT (11+ ) = 9.1 +2.6−3.0(for a single 1+ state)

N=ZNuclear Data Sheets 84(1998)

100Sn
99Sn
97In
95Cd
93Ag

log (ft)
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100Sn settings: 15 days

103Sb

Experiment Area
124Xe (36 pnA),EURICA
Tagged RI beam

Be 500 mg

133CdPID
Br - DE - Br – DE – Br
separation: 1011 s-1 -> 102 s-1
Br – TOF –DE
identification

ZA/Q

courtesy of S. Nishimura

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EURICA (EUroball-RIKEN Cluster Array)
12 EUROBALL Cluster
detectors, i.e. 84 Ge crystals

Euroball Cluster detectors
Support structure
Readout electronics
used for GSI-RISING
courtesy of S. Nishimura

RIKEN RIBF
(Japan)Installation completed in 2012 Feb.

ARIS Conference June 2014 @ TokyoWAS3ABI for 100Sn(Wide-range Active Silicon-Strip Stopper Array for Beta and Ion detection)
3 layers of 1mm DSSSDs
In total, 7,200 pixels(40-strips x 60 strips)+ 70 SSD strips
10 layers of 1mm SSSDs (7str)
design: TU-München/RIKEN

Decay
10 x 1mmcourtesy of K. Moschner

Implantation
3 x 1mm
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RIB Production
Ions reaching the final focal plane

Z

100Sn, (2100)

Ions correctly implanted in WAS3ABI100Sn, (1750)

A/Q

A/Q

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Cross-Sections 124Xe + Be

100Sn

this work
4 mm(mb)

345MeV,4 mm 1(mb)345MeV,8 mm 2(mb)

1GeV,22 mm 3(mb)EPAX
3.01(mb)~1 ×10-9

7.4 ×10-10

1.5 ×10-9

5.8 ×10-9

5.8 × 10-9

Most of the other nuclei arenicely calculated by EPAX!

Different energies ordifferent processes pronounced at
different target thicknesses??
1) H. Suzuki et al. Nucl. Inst. and Meth. in Physics B 317 (2013) 756–768
2) I. Celikovic PhD thesis, Université de Caen Basse-Normandie (2014)3) K. Straub PhD thesis , Technische Universität München (2011)
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98In

98In Decay
100Sn

counts /10ms

Decay time afterImplantation
1g9/2
2p1/2

2p3/2

counts /10ms

p n

1f5/2

T1/2_long = 0.95(6)(x) s
T1/2_short = 28(1)(x) ms

time after implantation [10ms]

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P.Kienle et al. Prog. Part. Nucl.
Phys. 46, 73 (2001)
D.Bazin et al. PRL 101,252501 (2008)

98In Fast Component

0 < Tdecay < 100ms 98In
(0+, T=1)

(12+)
(10+)

counts 2keV

pure gs.transition?

Eg [keV]

(8+)
(6+)
(4+)
(2+)

T1/2_short = 28.6(x) ms
using log(ft) = 3.487
QEC = 12.53 MeV
from CDE : 13.18 MeV
from AME : 13.74 MeV
CDE: M.S. Antony el al., Nuc.Data Tables 66 (1997)
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(0+)

98Cd

98In Daughter Component

9s < Tdecay < 15s 98Agcounts / 2keV

98Cd

Eg [keV]T1/2 = 9.2s
A. Płochocki et al. Zeitschrift für Physik A(1992), 342,1, pp 43-51

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98In Slow Component

200ms < Tdecay < 4s

 98In(9+, T=0)

(12+)
(10+)

counts / 2keV

2 counts 4157keV?
?

?

Eg [keV]

(8+)
(6+)
(4+)
(2+)

T1/2_long = 0.95(6)(x) s(0+)

98Cd
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98In Silicon EnergyCounts in 1mm window

200ms < Tdecay < 4scounts / 10keV

0 < Tdecay < 100ms

energy [keV]

see also: G. Lorusso et al., Phys. Rev. C 86 (2012)
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98In bp - decay(21/2+)

2052.9(17/2+)

1289.9(13/2+)

counts / 2keV

2343.3(9/2+)
097Ag

counts /10ms

Eg [keV]time after implantation [10ms]

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98In Ground State 98In(0+, T=1)

 98In(9+, T=0)~ 3 MeV EbEvaluate
Eb vs. Ep
BR bp/ECp

(12+)
(10+)

QEC=
12.5 MeV?
~ 3.2 MeV Ep

(8+)
(6+)
(4+)

(2+)

2343
2052

(21/2+)(17/2+)

1289(13/2+)

0(9/2+)

2.34 MeV Ex

97Ag

4.10 MeV Qp
(0+)

98Cd
ARIS Conference June 2014 @ TokyoN = Z-1 Nuclei
New or significantly improved T1/2
T1/2 = 25(x) ms,

99Sn

T1/2 = 31(x) ms,

97In

T1/2 = 26(x) ms, 3% bp? , 95Cd
Straub et al. GSI report 2010, 57ms (2 counts)

93Ag T
1/2 = 1s?

T1/2 = 0 (x) ms,

93Ag

T1/2 = 32(x) ms,91Pd

93Ag : T

1/2 = 300(-200 +600) ns

L=4 , g9/2 proton, Qp =1050(100) keV
AME12: 1510(710)keV
Delion et al., PRL96, 072501 (2006)

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Most Exotic Nuclei

decaysidentified

Isotope

gone

198Sn

1 count , 16ms

296In

3 counts, daughter? 694Cd

1 count , 1.5ms ?

992Ag

2 counts, 5ms ,15ms 490Pd

All counts have to be checked
for last implantation, 1st and 2nddecay PDFs
BG =1 / 20s

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100SnDecay of 100Sn
C. Hinke et at., Nature 486, 341–345 (2012)

T1/2 = 1.16(20) s
counts / 50ms

(NOT FULL STATISTICS)

T1/2 = 1.18(10)(x) scheck selection
according toPDFs
BG =1 / 20s
decay time (10ms)
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100Sn Delayed Gammas

436(51)

1st decay within 4 s

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100Sn Decay Gamma Rays
coincidences 96 – 141 – 436 – 1296
no coinc. 2048 – (141 || 436 ||1296)
ongoing background studies

all gammas
coincident to 141keV

C. Hinke et at., Nature486, 341–345 (2012)

ARIS Conference June 2014 @ TokyoGamma Efficiency from 98Cd Isomer
(12+)
(10+)

about 10000 counts
in the strongest line
- relative calibration- absolute calibration

counts / keV

Coincidences with 147keV no ab.
8.6%
4.9%
3.3%

(8+)
(6+)
(4+)

(0+)

98Cd

ion implanted 2mm

Eg (keV)(2+)

ARIS Conference June 2014 @ Tokyo time after implantation [10ns]

The ChallengeexpGTB

3xDSSD6142.8sg A / gV 2 ft

10xSSD~ Qb5 T1/2
exp 11   9.132..06
BGT
C. Hinke et at., Nature 486, 341–345 (2012)

Emax = 3.29 ± 0.20 MeV
E_Ge (keV)

A small calibration
error propagates
into a large
difference in BGTARIS Conference June 2014 @ Tokyo

E_Si (keV)Conclusion

List of achievements
First evidence
Discovery
98Sn

96In

99Sn

new half live
precise half live

97In

94Cd 95Cd
92Ag

90Pd

spectroscopy

93Ag

ongoinganalysis
at several places

91Pd

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RIBF009 Experiment
M. Lewitowicz*1, R. Gernhäuser*3, R. Krücken*4, S. Nishimura*5, H. Sakurai*6, H. Baba*5,B. Blank*7, A. Blazhev*8, P. Boutachkov*9, F. Brown*10, I. Čeliković,*1,*2, G. de France*1, P.
Doornenbal*5, T. Faestermann*3, Y. Fang*11, N. Goel*9, M. Gorska*9, S. Ilieva*12, T. Isobe*5,A. Jungclaus*13, G. D. Kim*14, Y.-K. Kim*14, I. Kojouharov*9, N. Kurz*9, G. Lorusso*5, D.
Lubos*3, K. Moschner*8, I. Nishizuka*15, J. Park*4, Z. Patel*16, M. Rajabali*4, S. Rice*16, H.
Schaffner*9, L. Sinclair*17, P. A. Söderström*5, K. Steiger*3, T. Sumikama*15, Z. Wang*4, H.
Watanabe*18, J. Wu*19, and Z. Xu*6

*1 GANIL,*2 Institute "Vinča", University of Belgrade*3 Technische Universität München*4 TRIUMF*5 RIKEN Nishina Center*6 University of Tokyo*7 CENBG*8 University of Cologne*9 GSI Darmstadt*10 Brighton University*11 Osaka University*12 TU Darmstadt*13 IEM CSIC, Madrid*14 Institute for Basic Science*15 Tohoku University*16 Surrey University*17 York University*18 Beihang University*19 Peking University

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EURICA Collaboration and Support
2012 Nov.-Dec.

2013 May

2012 June
Collaboration:Tohoku, Univ. Tokyo, Brighton Univ. Debrecen, Joseph Fourier, Osaka Univ. Peking, LPSC, IBS, Oslo, Consejo Sup. De
Inv. Cientificas, IPN Orsay, Padova, Leuven, SKKU, INFN, ANU, Köln, TU München, Fisica, Legnaro, ATOMKI, INFNMilano, INFN-Firenze, INFN-LNL, Univ. di Padova, Surrey, GSI, ANL, Yale, TRIUMF, Milano, Univ. Madrid, Tech.
Univ. Darmstadt, Univ. Istanbul, CNS, CEA, RCNP, Univ. Notre Dame, Inst. voor Kern-en Stralings Fysica, Hoseo Univ.,
Univ. Tsukuba, Inst. Plurid. Hubert Curien, and RIKEN
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