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Structure close to 208 Pb

Structure close to 208 Pb. Zsolt Podoly ák. The fragment separator. 370 implanted 212 Pb ions!. Time from production to spectroscopic analysis: ~ 300 ns. fragmentation or fission. Decay studies: -internal (isomers) -beta decay .

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Structure close to 208 Pb

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  1. Structure close to 208Pb Zsolt Podolyák

  2. The fragment separator 370 implanted 212Pb ions! Time from production to spectroscopic analysis: ~ 300 ns fragmentation or fission Decay studies: -internal (isomers) -beta decay M. Pfützner et al., Phys. Lett. B 444 (1998) 32. Very sensitive method

  3. ‘passive stopper’ experiments Exp. #3: 238U beam Exp. (test) #2: 238U beam Experiment #1 208Pb beam 208Hg, 209Tl Spokesperson: #1,2 Zs. Podolyák, #3 J.J. Valiente-Dobon, G. Benzoni Analysis by S. Steer (N<=126), N. Al-Dahan (N>126), T.Swan (σ)

  4. ‘active stopper’ experiments 208Pb beam 203,205,(206)Au 198,202Ir 200Os 194,196,198Re 190,192Ta Spokespersons: P.H. Regan & J. Benlliure Analysis by N. Alkhomashi, N. Al-Dahan, G. Farrelly, A.I. Morales et al.,

  5. N=126 nuclei below 208Pb (what was known) + 207Tl: D. Eccleshall, M. J. L. Yates, Phys. Lett. 19, 301 (1965). 206Hg: B.Fornal et al. Phys. Rev. Lett. 87(2001) 212501. Z=81 Z=80 Z=79 Z=78

  6. Particle identification GSI

  7. 204Pt 205Au 203Ir

  8. 205Au: three proton-hole nucleus Active stopper exp. Gammas Charged particles Zs. Podolyák et al., Phys. Lett. B 672 (2009) 116.

  9. Shell-model calculations (M.Górska, H.Grawe, H. Maier, A.Brown) • and (d):TBME from L.Rydstrom et al, NPA512(1990)217 (based on Kuo-Brown interaction) • (b) and (c): three TBMEs modified • Δ(d3/2 h11/2; d3/2 h11/2)7- = +135 keV • Δ(s1/2 d5/2; s1/2 d5/2)2+,3+ =+230 keV (monopole only) • Δ(d3/2 h11/2; s1/2 h11/2)6- changed to +0.160 MeV (fit for B(E2) • Good description of energies and B(EL)s S.Steer et al., Phys. Rev C78 (2008) 061302(R)

  10. 205Au πh11/2-2 s1/2-1 Orig. SM Mod. SM πh11/2-1 s1/2-2 πd3/2-1 s1/2-2 B(E2): 3.1 1.2(2) 1.7 W.u. Calc. H. Grawe

  11. 203Ir Mod. SM Orig. SM

  12. Future: further ‘down’ along the N=126 line (acc. exp.) 205Au: beta decay from 205Pt => will fix the πs1/2 orbital 203Ir: beta decay from 203Os (νg9/2) => will fix the πd3/2,πs1/2,πh11/2 202Os: isomeric decay I=(5),(7),(10) 202Os: beta decay of 203Ir (νg9/2) 8+ 2685 10+ 2673 8- 2558 5- 1932 7- 1893 shell model 4+ 1555 2+ 1181 202Os 0+ 0

  13. N>126, Z<82 nuclei (238U beam) Δq=0

  14. 206Hg 208Hg 209Tl N. Al-Dahan et al.

  15. Shell-model calc. (H. Grawe) TBME: from E.K. Warburton, PRC44, (1991) 233; are based on the Kuo-Herling realistic int. Single particle energies: 207Tl and 209Pb exp.

  16. ( νg29/2) states; 2+ mixed with πs-11/2d-13/2 B(E2)=1.22 W.u. SM B(E2)=1.95(39)-1.58(22) W.u. exp.

  17. 209Tl: Isomer: 17/2+; ( νg29/2) (πs-11/2) B(E2)=0.96 W.u. SM B(E2)=1.87(22)-1.51(18) W.u. exp. 17/2+->13/2+Δ 13/2+->9/2+ 137 keV 9/2+->7/2+Δ, allowed M1 7/2+->3/2+ 661 keV 3/2+->1/2+ 324 keV E2(+M1) 209Tl: previously from (t,α) and alpha decay. (t,α): C. Ellegaard, P.D. Barnes and E.R. Flynn, Nucl. Phys. A259 (1976) 435.

  18. N>126, Z<82 nuclei Mass measurement of 208Hg (GSI storage ring) ~1/(Δl+Δn) proton neutron i13/2 i11/2 g9/2 g9/2 Z=82 N=126 s1/2 p1/2 d3/2 f5/2 L. Chen et al., PRL102 (2009) 122503.

  19. N. Al-Dahan et al. submitted to PRL

  20. An example of an N=125 nucleus: 204Au Beta decay: A.I. Morales, J. Benlliure et al., Acta Phys. Pol. B 40, 867 (2009) Isomer: S.J. Steer et al., Int. J. Mod. Phys. E18, 1002 (2009) Shell model: M. Gorska T1/2=10(2) s 1-: 186, 336, 437, 686 keV

  21. Seniority isomers in n-rich Pb isotopes S350 experiment – 2.5g/cm2 Be target, 2g/cm2 S1 degrader, 0.7g/cm2 S2 degrader - Setting on 215Pb Pb isotopes

  22. 214,216Pb isotopes: neutron g29/2 8+ isomers J-J. Valiente-Dobon, G. Benzoni, Sept. 2009 Preliminary Partial statistics

  23. Population of isomers by two-proton knockout reaction in 206Hg Isomeric ratios fig. Exp. Theory 3.1 4.7 -> 4.3 22 19 -> 18 Total 10+ 5- (with feeding) E.Simpson, J.A. Tostevien et al.

  24. Summary: • Info through isomeric decays in: • - N=126: 205Au, 204Pt, 203Ir • - N=128: 208Hg, 209Tl • Comparison with shell-model • New measurements 214,216Pb • -future: higher beam intensity • AIDA • DESPEC

  25. The RISING Collaboration

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