1 / 22

From Magic 208 Pb to the 170 Dy Mid-Shell

From Magic 208 Pb to the 170 Dy Mid-Shell. Paddy Regan WNSL, Yale University, New Haven, CT and Dept. of Physics, University of Surrey, UK e-mail: p.regan@surrey.ac.uk. Outline. Rick’s thesis work (circa 1967, ‘before my time’)

darryl
Download Presentation

From Magic 208 Pb to the 170 Dy Mid-Shell

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. From Magic 208Pb to the 170Dy Mid-Shell Paddy Regan WNSL, Yale University, New Haven, CT and Dept. of Physics, University of Surrey, UK e-mail: p.regan@surrey.ac.uk

  2. Outline • Rick’s thesis work (circa 1967, ‘before my time’) • A hard act to follow....heavy, neutron-rich • DIC around 194Os (shape shifters). • ISOL work, pushing the limits, 182Yb. • Isomer fragentation spectroscopy at GSI • 202Pt single particle state inversion • 190W, sub-shell closure ? • Towards 170Dy, best K-isomer and SU(3) • Future prospects with RIA and others ?

  3. Neutron-rich isotopes between Z=66 and 82 are arguably the least studied region in the entire Segre chart to date.

  4. Importance of channel selection, circa. 1967.

  5. Ga.Sp data (2001), Surrey, Legnaro et al. WNSL data, c. 1967 Ge arrays and HI beams allow g-g(-g) coincs. to probe yrast states to ‘high spins’ (12+ in 192Os currently) and study eg. rotational alignments. 2+2->2+1 2+2->0+1

  6. First Identification of 182Yb: ISOL @ GSI 136Xe @ 11.4 MeV/u on 186W. Use GSI online mass-sep + tape-transport system to take A=182 isobars to Total Absorption Spectrometer (TAS). S. Al-Garni et al. Surrey/GSI/Liverpool

  7. Yb (Z=70) X rays but lack of e- coincs? Implication: 1 min. isomer populates GSB in 182Yb. (102, 228 keV) A=182 S. Al-Garni et al. Surrey/GSI/Liverpool)

  8. Production target Central focus, S2 Final focus, S4 primary beam Pb @ 1GeV/u dipole, Br degrader degrader MW=x,y scint catcher scint DE(Z2) scint (veto) Use FRS (or LISE3) to ID exotic nuclei. Transport some in isomeric states (TOF~ x00ns). Stop and correlate isomeric decays with nuclei id. eg. R. Grzywacz et al. Phys. Rev. C55 (1997) p1126 -> LISE C.Chandler et al. Phys. Rev. C61 (2000) 044309 ->LISE M. Pfutzner et al. Phys. Lett. B444 (1998) p32 -> FRS

  9. Gamma-gamma analysis on 200Pt isomer (21 ns!), Caamano et al. Nucl. Phys. A682 (2001) p223c; Acta Phys. Pol. B32 (2001) p763

  10. Podolyak et al. Phys. Lett. 491B (2000) 225

  11. Podolyak et al. Phys. Lett. 491B (2000) 225

  12. First id of ‘doubly mid-shell’ nucleus, 170Dy (N=104, Z=66). K=6+ isomers predicted for well deformed N=104 nuclei. TRS calcs (F.Xu) predict a very ‘stiff’, highly deformed prolate nucleus. Could be the best K-isomer? Data from M.Caamano et al. 33 ns isomer in 195Os (last stable 192Os), useful test of structure in prolate/oblate shape coexistence region. 194Os Wheldon et al. Phys. Rev. C63 (2001) 011304(R)

  13. TRS Calcs for 170Dy (Z=66, N=104, NpNn=352) (see PHR, F. Xu et al. PRC65 (2002) 037302)

  14. ‘Best’ K-isomer in SU(3) 170Dy Phys. Rev. C65 (2002) 037302 170Dy

  15. Pfutzner, Hellstrom, Mineva et al.

  16. Other ways to get around the gamma-flash problem? Segmented germanium detectors and digital electronics for each individual segment. EURYSIS 6 x 6 germanium, Surrey/Liverpool/Darebury UK Gamma-Ray Tracking Project.

More Related