1. Decay studies in Exotic, Neutron- Rich A~200 Nuclei Steven Steer for the Stopped Beam RISING Collaboration Dept. of Physics, University of Surrey Guildford, Surrey, GU2 7XH, UK s.steer@surrey.ac.uk

2. The RISING ‘Stopped Beam’ Campaign Passive Stopper : Isomer (gamma) decay Measurements Active Stopper : Isomer internal conversion electron and beta-decay measurements Today three experiments will be discussed. All three experiments focus on: Neutron-Rich, Z<82, A~200 nuclei Fragmentation of 208 Pb and 238 U This work is performed at GSI using the Fragment Separator and the RISING gamma-ray spectrometer

3. Overview of Experiment #1 Fragmentation of E/A = 1GeV 208 Pb with passive stopper (isomer gamma decay) >> N = 126 Z = 82 >> The first experimental information on excited states in 15 nuclides.

4. Previous Kowledge at N=126, Z<82 Z=80 PRL B. Fornal et. al. (2001) Z=81

5. Progress at N=126 : Z=77, 203 Ir and Z=78 204 Pt Data from 8,000 203 Ir nuclei 203 Ir 204 Pt

6. Shell-model calculations (M.Górska, H.Grawe, H. Maier, A.Brown) (a)and (d):TBME from L.Rydstrom et al, NPA512(1990)217 (based on Kuo-Brown interaction) (b) and (c): three TBMEs modified Δ(d 3/2 h 11/2 ; d 3/2 h 11/2 ) 7- = +135 keV Δ(s 1/2 d 5/2 ; s 1/2 d 5/2 ) 2+,3+ =+250 keV (monopole only) Δ(d 3/2 h 11/2 ; s 1/2 h 11/2 ) 6- changed to +0.160 MeV (fit for B(E2) Good description of energies and B(EL)s S.Steer et al., submitted to rapid Communications

7. Progress at N=126 : Z=79, 205 Au Isomer gamma decay Isomer conversion electrons Electron conversion data: Zs. Podolyák et al., submitted to Phys. Lett. B B(E2; 34) = 1.1 W.u. B(E3; 962) = 0.4 W.u.

8. (a)TBME from L.Rydstrom et al, NPA512(1990)217 (based on Kuo-Brown) (b)Modified (a) to get better desription of 204Pt 203 Ir N=126, Z<82, odd-Z decay schemes Z=81 Z=79 Z=77

9. 188 Ta → 188 W 190 Ta → 190 W 192 Ta → 192 W N. Alkhomashi, P.H. Regan et al., Experiment #2: beta decay studies

10. N=82 H. Grawe, K. Langanke, G. Martinez-Pinedo, Rep.Progr.Phys.70 (2007)1525. Larger differences at N=126 (lack of experimental data) N=126 N=126 towards r-process path

11. N. Aldahan, Zs. Podolyak et al. T 1/2 ~ 10 - 100 ns 208 Hg (Z=80;N=128) preliminary Experiment #3: N>126

12. The RISING Collaborators Named collaborators are for the 204 Pt research

13. In Summary Analysis beginning: Beta- and isomer- decay studies 208 Hg Experiment #2 Experiment #3 Experiment #1 27 isomers discovered 48 measured in total Analysis in progress: Beta-decay studies 188,190,192 W

14. N=122 isotones S.Yates et al., PRC37 (1988)1889. πh 11/2 -1 d 3/2 πh 11/2 -1 s 1/2 From RISING