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High-spin states in octupole -deformed 219 Ra

High-spin states in octupole -deformed 219 Ra. By Chris Wilson. Octupole deformation. I. Ahmad and P. Butler, Ann. Rev. Nucl . Part. Sci. 43 (1993). The light actinides. W. Nazarewicz and P. Butler, Rev. Mod. Phys. 68 (1996). Rotational consequences.

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High-spin states in octupole -deformed 219 Ra

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  1. High-spin states in octupole-deformed 219Ra By Chris Wilson Institute of Physics NPPD Conference 2011

  2. Octupole deformation I. Ahmad and P. Butler, Ann. Rev. Nucl. Part. Sci. 43 (1993) Institute of Physics NPPD Conference 2011

  3. The light actinides W. Nazarewicz and P. Butler, Rev. Mod. Phys. 68 (1996) Institute of Physics NPPD Conference 2011

  4. Rotational consequences W. Nazarewicz and P. Olanders, Nucl. Phys. A441 (1985) 420-444 Parity splitting Ratio of rotational frequencies Institute of Physics NPPD Conference 2011

  5. Condensation of octupole phonons S. Frauendorf, Phys. Rev. C77, 021304(R)(2008) Institute of Physics NPPD Conference 2011

  6. Experimental method Light-actinide nuclei 95 % 18O (95 MeV) + 208Pb → 226Th* 226Th* → 222Th* + 4n → 220Ra* + α2n → 219Ra* + α3n Institute of Physics NPPD Conference 2011

  7. Gamma-ray detection Gammasphere: 110 large-volume high-purity germanium detectors for use in gamma-ray spectroscopy experiments. Based at Argonne National Laboratory in Chicago Discrete gamma rays from evaporation residues Neutron peaks Continuum gamma rays from fast-fission Institute of Physics NPPD Conference 2011

  8. HERCULES Gammasphere(ball opened) HERCULES High-Efficiency Residue Counter Under Lots of Elastic Scattering 64 plastic scintillator detectors for evaporation-residue detectionW. Reviol et al. Nucl. Inst. Meth. A451 (2005) Institute of Physics NPPD Conference 2011

  9. Background reduction Pulseheight Time of flight Evaporation residues Institute of Physics NPPD Conference 2011

  10. Gamma-coincidence spectra Institute of Physics NPPD Conference 2011

  11. New high-spin states in 219Ra P. D. Cottleet al., Phys. Rev. C36 (1987) 2286 M. Wieland et al., Phys. Rev. C45 (1992) 1035 L. A. Riley et al., Phys. Rev. C62 (2000) 021301 Institute of Physics NPPD Conference 2011

  12. Rotational consequences Institute of Physics NPPD Conference 2011

  13. Rotational consequences Institute of Physics NPPD Conference 2011

  14. Rotational consequences Institute of Physics NPPD Conference 2011

  15. Rotational consequences Institute of Physics NPPD Conference 2011

  16. Summary • New high-spin states do not provide evidence for the condensation of rotationally-aligned octupole phonons. • 219Ra has either: • A spherical core unstable to both quadrupole and octupole vibrations, with the octupole vibration enhanced by the odd g9/2 neutron • A static octupole deformation strongly coupled to the odd g9/2 neutron • Greater detection sensitivity is required to probe the highest spin states Institute of Physics NPPD Conference 2011

  17. Thanks to UWS and my collaborators C.L.Wilson, J.F.Smith, R.Orlandi, S.D.Pain, K.M.Spohr, and D.A.Torres School of Engineering, University of the West of Scotland, Paisley, PA1 2BE, UK W.Reviol, D.G.Sarantites, X.Chen, and J.Snyder Department of Chemistry, Washington University, St. Louis, MO 63130 M.P.Carpenter, C.J.Chiara, R.V.F Janssens, B.P.Kay, F.G.Kondev, C.J.Lister, D.Seweryniak, and S.Zhu Argonne National Laboratory, Argonne, Il 60439 A.N.Wilson Department of Physics, Australian National University, Canberra ACT 0200, Australia Institute of Physics NPPD Conference 2011

  18. Enhanced E1 transitions Institute of Physics NPPD Conference 2011

  19. Rotational excited states g g g g States labelled by spin and parity (Jp) g g Ground state Institute of Physics NPPD Conference 2011

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