CEA Saclay CSNSM Orsay GANIL CaenIPN Orsay

Univ. SurreyCLRC DaresburyUniv. KeeleUniv. LiverpoolUniv. ManchesterUniv. PaisleyUniv. York

FZ JuelichFZ RossendorfGSI DarmstadtHMI BerlinTU/LMU MuenchenMPI HeidelbergTU DarmstadtUniv. BonnUniv. Koeln

KU Leuven

Univ. Milano INFN GenovaINFN LegnaroINFN/Univ. NapoliINFN/Univ. PadovaUniv. CamerinoUniv. Firenze

KTH StockholmUniv. LundUniv. Uppsala

NBI Copenhagen

IFJ KrakowIPJ SwierkUniv. KrakowUniv. Warszawa

Univ. Santiago de Compostela

Univ. MadridUniv. Valencia

IFIN, Bucharest

Nuclear Structure addressed at GSI/RISINGM.Górska, GSI Darmstadt

Rare Isotope Spectroscopic INvestigation at GSI: Oct. 2003-2009Rare Isotope Spectroscopic INvestigation at GSI: Oct. 2003-2009

Sofia, Bulgaria

rp-Process

Novae

and X-ray bursts

r-Process and Supernovae

Sp=0

Sn=0

RISING: Nuclear structure interestRISING: Nuclear structure interest

N=Z

Shell evolution/quenching

Isospin competition/symmetry

|Tz|=T =1: Iπ=0+

T=0 : Iπ=1+or (2j)+

Neutron numberPro

ton

num

ber

EXPERIMENTAL Features:EXPERIMENTAL Features:

- high energy beams >100MeV/u

- unambigous beam identification event by event

- cocktail or pure radioactive beam

- scattering experiments β~0.5:

coulomb excitation, knockout reaction

Ge array forward angles, εγ~5%

- stopped beam experiments:

isomers, beta and particle decay

Ge array spherical close geometry εγ~15%

First scattering experiments 2003-2005: Coulomb excitation,

One-, two-neutron knock-out

Ge Cluster

beam

Target chamber

CATE

RISING RISING -array for fast beams-array for fast beams

Ge Miniball

Typically: 100MeV/u, ε=0.06, ∆E/E=0.02

Relativistic Coulomb excitation of nuclei towards Relativistic Coulomb excitation of nuclei towards 100100SnSn

• 112,108Sn secondary beam with ~150MeV/u

• Au – Coulex target

A. Banu, PhD thesis, PR C72, 061305(R) (2005)A. Banu, PhD thesis, PR C72, 061305(R) (2005)

108Sn B(E2:2+→0+)EXP: 15.1 (3.3) W.u.TH1: 11.2 W.u. Morten Hjorth-JensenTH2: 11.5 W.u. Frederic Nowacki

2004: J. Cederkäll et al., REX-ISOLDE, 110Sn

2005: MSU, K.Starosta et al. 106-112Sn

asymmetry: p-h excitation? N=64 subshell closure?

M. Hjorth-Jensen, ν(d5/2g7/2s1/2h11/2), eν = 1e

2003

Sn chain: Enhanced Sn chain: Enhanced B(E2) systematics B(E2) systematics towards towards 100100SnSn

Shell Model: F. Nowacki et al., ν(d5/2g7/2s1/2h11/2), eν = 0.5e, π(g9/2g7/2d5/2d3/2s1/2), eπ = 1.5e

πν monopoles tuned toπESPEs and Z=50 shell gap

GSIRISING

P. Doornenbal et al., PRC(R) in print

A. Banu et al, PRC 72 061305(R) 2005

J. Cederkäll et al., PRL98, 172501(2007)

A. Ekström et al., PRL 101, 012502(2008)

C. Vaman et al., PRL 99, 162501(2007),

• A,Z event-by-event ID

• Time correlation ns - min

• Rate < 1 ion/hour

• Alignment → g, Q moment

+

• prompt flash

• isomeric ratio

• ray sequence

• spin-parity assignment

- + -

RISING: Stopped beamsRISING: Stopped beamsConvenor: P. H. Regan, University of SurreyConvenor: P. H. Regan, University of Surrey

100Sn

56Ni

132Sn

208Pb

62Ga

86Tc, 82Nb

54Ni, 50Fe108Zr

130Cd, 131In

204Pt, 205Au

Isomer scans

Decay measurementP. H. Regan

D. Rudolph

A. Gadea, A.Algora

B. Rubio, J. Fujita, W. Gelletly

T. Faestermann

A. Bruce

A. Jungclaus, M. Pfutzner, M.Gorska

P.H. Regan, J. Benliure, Zs. Podolyak

Zs. Podolyak

A. Blazhev, B. Wadsworth, P. Boutachkov, Zh. Liu

N=Z

N>Z

TechniquesTechniques – – Z vs A/Q plotZ vs A/Q plot Preliminary!!Preliminary!!

Prelim estimate > 2000 96Cd ions

Z

A/Q →

96Cd

B. Wadsworth et al.,

rp-proc

waiting

point

Expected

Known

Paestum 2003

9848Cd50

10050Sn50

Core excited states in large scale shell model

A. Blazhev et al., PRC 69, 064304 (2004)

V.I.Isakov, K.I. Erokhina Phys.At.Nucl.No.8,1431(2002).

F. Nowacki, priv. comm..

rp process path rp process path● @ T < 109 Kelvin when photodisintegration lifts (p,) – (,p) equilibrium

● MED of several 100 keV will influence the proton capture appreciably

• End of rp path near 100Sn due to fast decay beyond the double shell closure @Z=N=50

• 100Sn shell structure decisive for ß+/EC decay (Gamow-Teller) and waiting points

From:

H. Grawe, K. Langanke, G. Martínez-Pinedo, Rep.Progr.Phys. 70,1525 (2007)

M1 conversion

M1

E2

Decay scheme

(shell model)

Decay scheme

M. Karny et al. EPJA 27, 129 (2006)

100,102Sn ß+/EC decay

I = 6+ isomerism

1472

1969+1969

10049In 51

10249In53

10050Sn50

10250Sn52GT

GT

Particle identification spectrumParticle identification spectrum

100Sn

T.Faestermann et al.

In

Sn

Te

Sb

Cd

Ag

Pd

Rh

Ru

100Sn setting

T.Faestermann analysis: K.Eppinger, C.Hinke, TU München

Gamow-Teller decay in 100Sn

100100Sn setting check : Sn setting check : 9898CdCd

0+

8+

6+

4+

2+

0

1395

208322812428

12+ 6635

147

198

688

1395

4207s.e.

d.e.

new!?!

Langanke, K. & Martínez-Pinedo, G. Rev. Mod. Phys. 75, 819-862 (2003)

2+:Kautzsch, T. et al. Eur. Phys. J. A 9, 201-206 (2000)

Dillman et al., PRL, 91, 162503 (2003)

Astrophysics relevance for n-rich nuclei

204Pt

130Cd98Cd

70 72 74 76 78 80 820

500

1000

1500

60Nd

58Ce

56Ba

54Xe

52Te

48Cd

Ene

rgy

of 2

+ sta

te

Neutron number N

Indirect evidence for a N=82 shell quenchingIndirect evidence for a N=82 shell quenching

Kautzsch et al., Eur. Phys. J. A9 (2000) 201

indication from ß-decay studies at ISOLDE

Can the anomalous behaviour of 2+ energies in the Cd isotopestowards N=82 be attributed to a change in the N=82 shell gap ?

130130Cd from fission and fragmentationCd from fission and fragmentation

Lucia Caceres PhD theses Lucia Caceres PhD theses

A. Jungclaus et al., PRL 99, 132501 (2007)A. Jungclaus et al., PRL 99, 132501 (2007)

-coincidences130Cd

100100Sn vs Sn vs 132132SnSn N=50 TBME scaled by (88/132)1/3 to N=82 SPE from 99In and 131In, respectively

No dramatic shell quenching!No dramatic shell quenching!

B(E2) = 1.3(4) 1.45 (2.0) 1.2 1.1/1.3(2) WU

A. Blazhev et al., PRC 69, 064304 (2004) A. Jungclaus et al., PRL 99, 132501 (2007)A. Jungclaus et al., PRL 99, 132501 (2007)

(p1/2,g9/2)(s,d,g7/2,h11/2)

H. Grawe

Ir=27% Ir=13%

131131In spectraIn spectra131131In spectraIn spectra

M.G., L. Caceres et al., submitted to PLB

Z=49

E4: ≤1.6 2.4 WU

Shell model :

p 2p1/2,1g9/2,1g7/2,2d5/2

n 3s1/2,1h11/2,2d3/2,2f7/2,

(1h9/2)

1p1h excitations only !

132Sn single particle /

hole energies

Two-body interaction

from one major shell higher at 208Pb

PRC 44, 233 (1991)

scaled by A-1/3 and for

orbital overlap

N=82 gap at Cd:4.33 MeV vs. 4.94 MeV at Sn

More precisely...

The solar r-process abundance problem

The abundance deficiency (´´trough´´) is due to the changing slope in the neutron separation energy S2n (´´saddle point structure´´) in some mass formulae.

From: H. Grawe, K. Langanke, G. Martínez-Pinedo, Rep. Progr. Phys. 70,1525 (2007)

Depletion of progenitors !

´´trough´´

´´saddle point´´

Monopole evolution of the N=82 gapMonopole evolution of the N=82 gap

Shell quenching for very n-rich nuclei Shell quenching for very n-rich nuclei Potential shape: Wood Saxon (WS) Potential shape: Wood Saxon (WS) → Harmonic Oscillator (HO)→ Harmonic Oscillator (HO)

T.R. Werner, J. Dobaczewski, W. Nazarewicz, Z. Phys. A358 (1997) 169

stable nucleus

neutron rich

nucleus

need for intense radioactive nuclear beams

Conclusion:

● Fragmentation + fission of relativistic beams + FRS + RISING

● Precision spectroscopy of exotic nuclei → tuning of effective NN

interaction

● Monopoles determine shell evolution

● Nuclear structure and astrophysics

Future :

● FAIR + Super-FRS + HISPEC/DESPEC → intensity, acceptance,

efficiency, selectivity

● Modern effective NN interactions, SM techniquesNEUTRON DETECTOR

GE γ-ARRAY

RADIOACTIVEBEAM

HISPECHISPEC DESPECDESPEC

(fast, slow beams) (stopped beams)(fast, slow beams) (stopped beams)

Collaboration Collaboration A.Algora(Valencia), W.Gelletly(Surrey), A.Gadea (Legnaro), Y.Fujita(Osaka), B. Rubio(Valencia),

K.Langanke, G. Martinez-Pinedo, K. Sieja(GSI),

F. Nowacki (Strasbourg), P.Regan(Surrey), G. Neyens(KU Leuven),

H. Grawe (GSI), J. Tostevin (Surrey), P. Boutachkov(GSI), A. Blazhev (Köln),

T. Faesterman(Munich), B. Wadsworth(York), Zh. Liu(Edinburg), L.Caceres (GSI/Madrid), K. Eppinger, C. Hinke (TU Munich), F.G. Molina(Valencia),

A. Garnsworthy(Surrey/T), A. Banu(GSI), A. Jungclaus (Madrid),

M. Pfützner (Warsaw), Zs. Podolyak(Surrey), S. Pietri(Surrey/GSI),

P. Doornenbal(GSI/RIKEN), N.Brown(Köln), T. Brock (York),

S. Steer(Surrey), G. Farrelly(Surrey)

RISING/GSI group: H.J. Wollersheim, J.Gerl, P. Bednarczyk,

P. Boutachkov, C. Domingo, J. Grebosz, I. Kojoharov, H. Schaffner,

R. Hoischen(GSI/LUND)...

FRS group: H. Weick, H. Geissel, Y. Litvinov, Ch. Nociforo..

...and many others within the RISING collaboration