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RISING ( R are IS otope IN vestigation at G SI): Phases and recent results

CLRC Daresbury Univ. Keele Univ. Liverpool Univ. Manchester Univ. Paisley Univ. Surrey Univ. York. FZ Juelich FZ Rossendorf GSI Darmstadt HMI Berlin LMU Muenchen MPI Heidelberg TU Darmstadt Univ. Bonn Univ. Koeln. Univ. Milano INFN Genova INFN Legnaro INFN/Univ. Napoli

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RISING ( R are IS otope IN vestigation at G SI): Phases and recent results

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  1. CLRC Daresbury • Univ. Keele • Univ. Liverpool • Univ. Manchester • Univ. Paisley • Univ. Surrey • Univ. York • FZ Juelich • FZ Rossendorf • GSI Darmstadt • HMI Berlin • LMU Muenchen • MPI Heidelberg • TU Darmstadt • Univ. Bonn • Univ. Koeln • Univ. Milano • INFN Genova • INFN Legnaro • INFN/Univ. Napoli • INFN/Univ. Padova • Univ. Camerino • Univ. Firenze • Univ. Demokritos • CEA Saclay • CSNSM Orsay • GANIL Caen • IPN Orsay • KTH Stockholm • Univ. Lund • Univ. Uppsala • IFJ Krakow • IPJ Swierk • Univ. Krakow • Univ. Warszawa • Univ. Leuven • NBI Copenhagen RISING (RareISotopeINvestigationatGSI): Phases and recent results M. Górska, GSI Darmstadt • Australian Nat. Univ., Canberra

  2. RIBat GSI The Accelerators: • UNILAC(injector) E<11.5 MeV/n • SIS 18Tmcorr. U 1 GeV/n Beam Currents: 238U - 108 pps some medium mass nuclei- 109 pps (A~130) γ spectroscopy setup: FRS provides secondary radioactive ion beams: • fragmentation or fission of primary beams • high secondary beam energies: 100 – 700 MeV/u • fully stripped ions

  3. Z ToF A/Q Y X Secondary Beam Identification productiontarget multiwire chamber; beam position scintillator RISING MUSIC ionization chamber; Z scintillator b

  4. TheRISINGcampaigns The “beam cocktail” : 238U fission fragments recorded at the FRS The selected unstable fragments can be: Phase I: Fast beam campaign • used at relativistic velocities • or stopped and investigated (delayed particle or γ-emission) • or slowed down to the Coulomb barrier energy before impinging the secondary (reaction) target Phase II: Current campaign The feasibility has to be checked yet Each campaign requires a dedicated Ge-detector arrangement !

  5. 104-112Sn 134Te 185-187Pb 134Ce, 136Nd 69Br 132Sn 53Ni 68Ni 88Kr 36Ca 58Cr • Shell structure of instable magic nuclei • Symmetry along the N=Z line • Collective modes, E1 strength distribution • Shapes and shape coexistence N=Z 32,34Mg Phase I : Fast beams, Oct. 2003 – May 2005Physics program - Nuclei of interest convener: P. Reiter, University of Cologne

  6. Reactions used with fastRIBs convener: P. Reiter, University of Cologne Coulomb excitation (Au secondary targets): • Low spins ( Mg=1) • Forward scattering (q < 3°) • High excitation energy ( GDR population ) Fragmentation ( Be secondary targets): • Higher spins ( Mg>1)

  7. Y X ToF DE CATE g MW MW Target Si CsI Qg E Qp Secondary reaction product identification productiontarget multiwire chamber; beam position scintillator reaction target MUSIC ionization chamber; Z CATE Si-CsI arrays; (X,Y), Z,A scintillator b HECTOR BaF2 detectors Ge-Cluster and MINIBALL detectors

  8. Gamma spectroscopy with fast beams ~ 3% E=1.3 MeV D = 70 cm Lorentz boost (+) Doppler broadening (-) Atomic background(-)  target  = 0.43 Detector opening angle Dq=3° Composite detector  = 0.57 DEg0/Eg0 [%]  = 0.43  = 0.11 1 Ge-Cluster detector qlab [deg]

  9. Ge Cluster detectors BaF2HECTOR detectors Ge Miniball detectors Phase I : RISING g-array for fast beams Target chamber CATE beam

  10. New Shell Structure at N>>Z On the pathway of magicity from N=40 to N=32 Collaboration:Bonn, Cologne, GSI, Lund Spokesperson: P. Reiter, H. Grawe, H. Hübel f 5/2 Neutron-rich Ca-, Ti-, Cr-Isotopes • protons are removed from the pf7/2 shell • weaker pf7/2 –nf5/2 monopole interaction • nf5/2moves up in energy • possible shell gaps at N=32 and N=34?

  11. New Shell structure at N>>ZRelativistic Coulex in N=28-34 nuclei A. Bürger et al., Phys. Lett B622, 29 (2005) Similar results for 52,54,56Ti (MSU) D.-C. Dinca et al., Phys. Rev. C71 (2005) 041302 Plunger: 56Cr: 11.2 ± 1.5 W.u Calculations: T. Otsuka et al., Phys. Rev. Lett. 87, 082502 (2001) T. Otsuka et al., Eur. Phys. J. A 13,69 (2002) M. Honma et al., Phys. Rev. C 69, 034335 (2004) E. Caurier et al., Eur. Phys. J. A 15, 145 (2002)

  12. Mirror symmetry of new (sub)shell closures : 36S – 36Ca H. Grawe, et al. N=Z Is N,Z=14(16) shell stabilisation and N=20 shell quenching in 32Mg20 symmetric in isospin projection Tz? • monopole part of two-body interaction • small neutron binding energy 14O 16O 14C

  13. Secondary fragmentation of 37Ca beam Double fragmentation reaction: 40Ca (630 AMeV) + 9Be → 37Ca (200 AMeV ) + 9Be (0.7 g/cm2) 38Ca (<1 %) 37Ca (85 %) 2*103 p/sec 36K (14 %) Ca K ~800 keV DE Ar EPAX cross section ratios: Cl S P Si Al Mg Na E

  14. 36Ca E(2+) preliminary result P. Doornenbal et al., to be published Cluster 3014(20) keV Miniball BaF2 36S E(2+) – 36Ca E(2+) = 276 keV (confirmed by GANIL) in a qualitative agreement with USD1 calculation using SPE from 17O and 17F => major part of the displacement: Thomas-Ehrmann shift [1] B.A. Brown, B.H. Wiedenthal: Ann. Rev. of Nucl. Part. Sci. 38, 29 (1988)

  15. Lineshape energy resolution and line shape • detector opening angle • DE=13 keV @ 800 keV • energy/momentum transfer from fragmentation DE=14 keV @ 800 keV (including opening angle) • energy loss in target • total energy spread: DE=38 keV @ 800 keV • lineshape effects due to lifetime Be-target: 0.7 g/cm2 bin=0.54 Dt~24ps 36K Inner ring Q~160

  16. A. Banu et al., Phys. Rev. C 72, 06305(R) (2005) Primary beam: 124Xe: 700 MeV/u Secondary beam: 108,112Sn: 147 MeV/u, Au-target: 400 mg/cm2 112Sn (2+  0+) 108Sn (2+  0+) Relativistic Coulomb Excitation of Nuclei Near 100Sn Collaboration:Lund, Uppsala, Stockholm, Keele, Legnaro, Warsaw, Debrecen, Liverpool, Surrey, York, GSI Spokesperson: C. Fahlander, Lund, M. Gorska, GSI ORNL data RISING B(E2, 2+->0+) values provide E2 correlations related to core polarization. Lifetime measurements hampered by isomeric 6+ states in even Sn isotopes 2+->0+ decay too fast for electronic timing methods. Coulomb excitation of instable Sn isotopes

  17. theory (neutron valence and100Snas closed-shell core) theory (neutron valence+ proton core excitations and 90Zras closed-shell core) This work t=4 t=2 t=4 t=0 Neutron number B(E2 ) e2 b2 SM calculations Neutron/proton single-particle states in a nuclear shell-model potential: •••••••• Complementary method REX-ISOLDE: J. Cederkäll et al.,108,110Sn New data: MSU, K. Starosta et al., 106-108Sn

  18. 136Nd 21+ 0+ counts 22+ 21+ 22+ 0+ 4+1 2+2 2+1 0+ energy [keV] Triaxiality in even-even core nuclei of N=75 isotones Spokesperson: T.R. Saito (GSI), K. Starosta (MSU) Predicted by MC calulation: T. Otsuka et al, PRL 86 (2001) 1171 Triaxiality g-Softness First observation of a second excited 2+ state populated in a Coulomb experiment at 100AMeV using RISING

  19. RISING Fast beam collaboration: P. Reiter

  20. Phase II a: g-factors of isomeric beams (TPAD)Oct.- Dec. 2005 Convener: G. Neyens, K.U. Leuven

  21. degrader Slits Setup magnet + 8 RISING detectors (top view) • Spin-alignedsecondary beam • A t=0 signal for g-decay timing • A collimator to avoid beam scattering • An implantation foil • A magnet with field up to 1.1 T • 8 Cluster detectors from RISING (e ~ 3%)

  22. fragmentation fission Performed Experiments - g-factors around 132Sn (D. Balabanski, M. Hass) - g-factor of 11- in 192Pb (A. Maj, J. Gerl) - spin-alignment in high-energy fission (G. Neyens, G. Simpson) - g-factors around 132Sn (G. Simpson, G. Neyens) RISING: unique facility to study g-factors and quadrupole moments of spin-aligned isomeric beams not accessible at other places: - lifetime range 100 ns – 100 ms (not at ISOL facilities) - in neutron rich nuclei with mass A>70 (not with intermediate energy fragmentation) (not with fusion-evaporation)

  23. First spectra 136Xe fragmentation data: minimum 30000 counts requested for the R(t) 127Sn 8h data ~5000 counts in the ph peak measurement ~4 days 127Sn 127Sn

  24. g-RISING collaboration: G. Neyens PARTICIPANTS 1. K.U. Leuven, Belgium: S. Mallion, G. Neyens, P. Himpe, N. Vermeulen, D. Yordanov 2. University of Sofia, Bulgaria: A. Blazhev, R. Lozeva, P. Detistov, L. Atanasova, G. Damyanova 3. CEA, Bruyères le Chatel, France:G. Bélier, J.M. Daugas, V. Meot, O. Roig 4. ILL Grenoble, France:G. Simpson, I.S. Tsekhanovich 5. CENBG Bordeaux, France: I. Matea, K. Turzó 6. GSI-Darmstadt, Germany: F. Becker, J. Gerl, H. Grawe, M. Gorska, I. Kojuharov, T. Saitoh, H.J. Wollersheim 7. IKP Koeln, Germany: J. Jolie, A. Richard, A. Scherillo 8. IKHP Rossendorf, Germany: R. Schwengner 9. The Weizmann Institute, Israel:S. Chamoli, G. Goldring, M. Hass, B.S. Nara Singh, I. Regev, S. Vaintraub 10. University of Camerino, Italy: D. Balabanski, G. Lo Bianco, K. Galdnishki, A. Saltarelli, C. Petrache 11. University of Milano, Italy: G. Benzoni, N. Blasi, A. Bracco, F. Camera, B. Million, S. Leoni, O. Wieland 12. IFJ-PAN Krakow, Poland:P. Bednarczyk, J. Grébosz, M. Kmiecik, M. Lach, A. Maj, K. Mazurek, K.H. Maier 13. Warsaw University, Poland: M. Pfűtzner, A. Korgul W. Méczyński, J. Styczeń14. NIPNE, Bucharest, Romania: M. Ionescu-Bujor, A. Iordachescu, G. Ilie 15. Universidad Autonoma de Madrid, Spain: A. Jungclaus 16. ISOLDE-CERN, Switzerland:G. Georgiev 17. Manchester University, U.K: A.G. Smith, R. Orlandi 18. University of Surrey, UK: Zs. Podolyàk, P.Regan, P.M. Walker

  25. Phase II b: Stopped beams Feb. 2006 - Convener: P.H. Regan, University of Surrey 5 clusters at 510, 5 clusters at 900, 5 clusters at 1290 all at 209.8mm Photopeak efficiency17.2% at 1.3MeV 8 BaF2 detectors (185-220mm) H. Mach J. Simpson CCLRC Daresbury

  26. Status on 01 Feb.:

  27. Physics Case for the Stopped Beam RISING Campaign P.H. Regan (convenor) • Structure Around 100Sn • Neutron deficient nuclei with 28<Z<50 • Fission fragment studies • The Neutron-rich Hf-Pt region • Isomer and Particle Decay Probes of Shape Coexistence Around Z=82 implantation-decay: time correlation - active catcher position correlation - granularity impl. of several ions: thickness and area energy of the ion and the emitted particle 3 double-side silicon-strip detectors - surface 5x5 cm2 - thickness 1 mm - 2 x 16 3.125 mm strips - manufactured by MICRON

  28. Stopped Beam RISING collaboration: P.H.Regan PARTICIPANTS CENBG Bordeaux, France: B. Blank GSI-Darmstadt, Germany: J.Gerl, H.J.Wollersheim, F.Becker, H.Grawe, M.Gorska, P.Bednarczyk, N.Saitoh, T.Saitoh IKP Koeln, Germany: J. Jolie, P. Reiter, N. Warr, A. Richard, A. Scherillo, N. Warr TU Munchen: R. Krücken, T. Faestermann University of Camerino, Italy: D. Balabanski, K.Gladnishki, IFJ PAN Krakow, Poland: A. Maj, J. Grebosz, M. Kmiecik, K. Mazurek Warsaw University, Poland: M. Pfűtzner Universidad Autonoma de Madrid, Spain: A. Jungclaus Universidad de Santiago de Compostela, Spain: D. Cortina Gil, J. Benlliure, T. Kurtukian Nieto, E. Caserejos IFIC Valencia, Spain: B. Rubio INFN-Legnaro, Italy: A. Gadea, G. deAngelis, J.J. Valiente Dobon, N. Marginean, D. Napoli, INFN-Padova, Italy: E. Farnea, D. Bazzacco, S. Lunardi, R. Marginean University and INFN-Milano: A. Bracco, G. Benzoni, F. Camera, B. Million, O. Wieland, S. Leoni University of Surrey, UK: Zs. Podolyàk, P.H. Regan, P.M. Walker, W. Gelletly, W.N.Catford, Z. Liu, S. Williams University of York, UK: M.A. Bentley, R. Wadsworth University of Brighton, UK: A.M. Bruce University of Manchester, UK: D.M. Cullen, S.J. Freeman University of Liverpool, UK: R.D. Page University of Edinburgh, UK: P. Woods, T. Davinson CLRC Daresbury, UK: J. Simpson, D. Warner Uppsala University, Sweden: H. Mach Lund University, Sweden: D. Rudolph Lawrence Berkeley National Lab, USA: R.M. Clark University of Notre Dame, USA: M. Wiescher, A. Aprahamian Youngstown State University, Ohio, USA: J.J. Carroll Debrecen, Hungary: A. Algora

  29. Summary First experiments and results from Phase I: • Coulomb excitation of 2+1in 108,112Sn • Coulomb excitation of 2+ in 54,56,58Cr • Spectroscopy of fragmentation products around 37Ca • Coulomb excitation of 2+1 and 2+2 in134Ce, 136Nd More results: - Mirror nuclei after fragmentation of 55Ni • Knock out close to 132Sn • Life time measurements after 34Si fragmentation • Symmetry along the N=Z line: 69Br • Collective modes and E1 strength distribution: 68Ni • g-RISING • stopped beams starting in February

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