Relativistic Coulomb excitation of nuclei Relativistic Coulomb excitation of nuclei near near 100100SnSnC.Fahlander, J. Eckman, M. Mineva, D. Rudolph, Dept. Phys., Lund University, Sweden

M.G., A.Banu, A. Blazhev, H.Grawe, T.R.Saito, et al., GSI, Darmstadt, Germany

J.Nyberg, et al., Dept. Rad. Sci., Uppsala University, Sweden

B.Cederwall, et al., RIT, Stockholm, Sweden

M.Bentley et al., Dept. Phys., Keele University, UK

G.de Angelis, A. Gadea et al., LNL, Padova, Italy

M.Palacz, et al., HIL, Warsaw University, Poland

D.Sohler, et al., INR, Debrecen, Hungary

P.Nolan, et al., Liverpool University, UK Surrey 29-30 March, 2004 RISING STOPPED BEAM PHYSICS WORKSHOP

100100Sn region studied with relativistic beamsSn region studied with relativistic beams

B(E2: 2+ → 0+) structure of isomers

Experimental conditions

Fusion symmetric reaction

EUROBALL, GASP + Ancillaries

MSEP β decay

Fragmentation Coulex

Isomers β decay → T. F. talk

Physics interest

• Shell structureSPE

• Residual Interaction E2 correlations

• Shell gap

• Core excitation:E2E3

• Magnetic rotationM1 bands

E3E2 E2

I, E

ExperimentalExperimental DetailsDetails

Primary beam: 124124Xe, 700 AMeVXe, 700 AMeV

Production target: 99Be, 4 g/cmBe, 4 g/cm22

Coulex target: 197197Au, 0.4 g/cmAu, 0.4 g/cm22

Nuclei of interest: 108108Sn (58h),Sn (58h),112112Sn(28h), ~150 AMeVSn(28h), ~150 AMeV ~ 3-5 kHz intensity~ 3-5 kHz intensity

Fragment identificationFragment identification

projectile

target

outgoing

A/Q

Z

108Sn

before the target (FRS)before the target (FRS)

Z

A/Q

Analysis in progress...

Simulated experimental spectrawith realistic 108Sn beam intensity and background

including 2+ lifetime effects and estimated cross section

Energy [keV]

Cou

nts

Next step after succesful analysis, 106Sn, 104Sn (new proposal)

pessimistic expected

56Ni and 100Sn similarities

12+:76Ni

8+:130Cd

54Fe

A. Blazhev et al., PRC submittedGDS: F.Nowacki, Nuc. Phys. A 704 (2002) 223cESM: H. Grawe et al., NS98 AIP CP 481 (1999) 177

Core excited states in 98Cd

eπ = 1.3(2) eπ = 1.1

Shell Model calculations GDS

100Sn shell gap:

12+: πg9/2-2νg9/2

-1(d5/2,g7/2)

dominated by strong binding

πg9/2-2νg9/2

-1 ≈ πg9/2-2

E(12+)-E(8+) – measure of the shell gap

EXP – SM = -325 keV for ESM (6.78 MeV)6.46 MeV

-34 keV for GSD (6.5 MeV)6.47 MeV

Esg = 6.46(15) MeV

Outlook:

E2 correlation Coulex SPE structure and residual interaction isomers-stopped beam