1. Paddy Regan for the Stopped Beam Rising Collaboration Dept. of Physics, University of Surrey p.regan@surrey.ac.uk The (Stopped Beam) RISING Experimental Campaign at GSI: The Mapping of Isomeric Decays and Beta-Delayed Spectroscopy in Highly Exotic Nuclei

2. RISING Rare Isotopic Spectroscopic INvestigations @ GSI = 15 x Cluster germaniums for (the most) exotic gamma-ray spectroscopy

3. Stopped RISING Physics Aims & Philosophy Study the evolution of single-particle / shell structure (shell melting ?) as a function of N:Z ratio. – 56 Ni (N=28 ; Z=28) 100 Sn (N=50: Z=50) – 132 Sn (N=82 : Z=50) – 208 Pb (N=126 : Z=82) Study the structure of nuclei with the most exotic proton-to-neutron ratios: – Proton drip-line N=Z – Neutron-rich ‘terra incognita’. Nuclear ‘symmetries’ and relevance of quantum numbers: – Isospin, T(N:Z ratio) – Nuclear Deformation,  2 (p-n interactions) – Angular Momentum Projection, K (axial symmetry) – Critical Point Symmetries e.g., X(5) Reaction mechanism studies in fragmentation.

4. Physics aims of the RISING stopped beam campaign 82 Nb, 86 Tc 54 Ni 130 Cd 204 Pt 106 Zr Terra Incognita ~ 190 W

5. Stopped RISING Array @ GSI: 15 x 7 element CLUSTERs Photopeak efficiency >10% at 1.3 MeV. XIA-DGF electronics

6. Best  -spectrometer ever used in isomer spectroscopy ! The RISING  -ray spectrometer 15 EUROBALL Cluster (105 Ge crystals) digital signal processing via 30 XIA DGF modules Absolute efficiency [%]  -energy [keV] 200600100014000 10 0 20 30 40 DGF TDC MSU GSI  detection efficiency very high  -ray efficiency high granularity (prompt flash problem) S. Pietri et al., Acta Phys. Pol. B38 (2007) p1255

7. Particle Identification N=Z line Sum of data from 90 Rh, 86 Tc and 82 Nb settings with 107 Ag beam A.B. Garnsworthy et al., Acta Phys. Pol. B38 (2007) p1265 & L. Caceres et al., Acta Phys. Pol. B38 (2007) p1271

8. 82 Nb 86 Tc T 1/2 = 133(20) ns T 1/2 = 1.59(20)  s

9. g 9/2 Search for the 8 + (g 9/2 ) -2 seniority isomer in 130 Cd two proton holes in the g 9/2 orbit 6-proton-knockout from 136 Xe: A. Jungclaus fission of 238 U: M. Górska, M. Pfützner June/July 2006 M. Górska et al., Phys. Rev. Lett. 79 (1997)

10. Singles  -spectrum in delayed coincidence with implanted 130 Cd ions T 1/2 =220(30) ns TIME ENERGY

11.  coincidence spectra 128 138 539 1325 Gate: 128 keV Gate: 138 keV Gate: 539 keV Gate: 1325 keV 0+0+ (2 + ) (4 + ) (6 + ) (8 + ) SM 130 Cd 82 48 1346 1889 2094 2207 0+0+ 2+2+ 4+4+ 6+6+ 8+8+ 1325 539 Decay of the 8 + isomer in 130 Cd T 1/2 =173nsT 1/2 =220(30)ns New results give no evidence for a N=82 shell quenching A. Jungclaus, L. Cáceres et al.,submitted to Nature

12. Shell structure south of 208 Pb Spokesperson: Zsolt Podolyak, Surrey cold fragmentation of 208 Pb@1 GeV/u main aim: spectroscopy of N=126 isotones 206 Hg, 204 Pt and 202 Os 204 Pt 202 Os Related reaction theory by J.Tostevin et al.,

13. 204 Pt populated via 4-proton-knockout from 208 Pb T 1/2 =8.41(16)  s T 1/2 =152(16) ns short isomer: long isomer: S. Steer, Zs. Podolyak et al., Acta Phys. Pol. B38 (2007) p1283

14. N=126 isotones: (  h 11/2 ) -2,4 I  =10 + isomers 206 Hg Z=80 B. Fornal et al. PRL 87 (2001)212501  s 1/2 -1 d 3/2 -1  s 1/2 -1 h 11/2 -1  d 3/2 -1 h 11/2 -1  h 11/2 -2 SM 92(8) ns 2.15(21)  s 204 Pt Z=78 152(16) ns 8.41(16)  s  d 3/2 -1 d 5/2 -1  d 5/2 -1 h 11/2 -1 ? Results require modification of SPE and/or interactions ! SM Z. Podolyak, S. Steer et al., PRL, in preparation

15. Active Stopper RISING Isomer spectroscopy requires isomers! Would like to be able to do beta-delayed spectroscopy on (neutron-rich) fragments. Problem….implanting ~10 GeV energy followed by ~200 keV in same pixel. Solution? ‘Logarithmic’ pre-amps.

16. 5 cm x 5 cm DSSSD (16 strips by 16 strips = 256 pixels) 3 positions across focal plane, room for 2 detectors deep.

17. R. Kumar et al.,

19. 205 Au 126 electron conversion!! h 11/2 → d 3/2 M4 transition (half-life a few seconds…..) New single particle (hole) information around 208 Pb core. K L

20. On-line beta-delayed gated 190 Ta ions….. Transitions fed in daughter 190 W nucleus by beta decay. 207 keV 2 + → 0 + N. Al-Khomashi, PhD thesis First time we see same nucleus via both isomer decay AND beta-decay.

21. 190 W isomer decay from 208 Pb beam

22. Friday, April 20 Exp.-SpokespersonCo-Title N° Spokesperson Regan, P. Introduction to RISING Proposals: Status report of the stopped beam RISING campaign using passive and active stoppers S337Gadea, A. Structure of 132In populated in the beta-decay of 132 Cd: the nf7/2 pg9/2-1 multiplet on the doubly magic 132 Sn core S340Sohler, D. Single particle energies in the vicinity of 78 Ni S342Balabanski, D. Quadrupole moment measurement of the 8+ isomer in 96 Pd using the RISING stopped-beam set up S343Simpson, G.Lozeva, R. Isomeric states containing the neutron g9/2 orbit in the very neutron-rich mass 95 region S344Simpson, G.Lozeva, R.Measurements of high-spin microsecond isomers near 132 Sn S346Bruce, A. Shape evolution near 110 Mo S347Podolyak, Z.Along the N=126 closed shell S348Gerl, J.Patra, S. K.; Palit, R.Search for the superheavy isotope 162 Sm S350Benzoni, G.Valiente Dobon, J. J.Moving along Z=82, beyond the doubly-magic 208 Pb nucleus S352Blazhev, A.Wadsworth, R.Study of the N>=Z proton dripline nuclei 96, 97, 98 Cd with astrophysical consequences S353Caceres, L.Regan, P. Structure of the odd-odd N=Z nuclei in the vicinity of 100 Sn: high spin isomers in 90 Rh studied through GT  -decay GSI-EA (Fri. 20 th April 2007) 11 New Stopped RISING Proposals All with UK involvement, 4 with UK (co)spokespersons)