In-beam and decay spectroscopy of transfermium elements

1. In-beam and decay spectroscopy of transfermium elements 251Md Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

2. Contents • Focal plane decay studies – 255Lr,253No • In-beam electron spectroscopy – 254No • In-beam gamma-ray spectroscopy – 254No, 250Fm, 251Md • Future developments Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

3. Focal Plane Decay Studies Recent Experiments: • 255Lr alpha decay (P.T. Greenlees et al., JYFL) also studied in GANIL (Ch. Theisen et al., Saclay) and at GSI in decay of 259Db (F.P.Heßberger et al., GSI) • 255No alpha decay/254No Isomer (JYFL expt - R.-D. Herzberg et al., Uni. Liverpool) 254No Isomer also studied at ANL (T.L. Khoo et al.,ANL) • 253No alpha decay (JYFL expt - R.-D. Herzberg et al., Uni. Liverpool) (GSI expt - F.P.Heßberger et al., GSI) Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

4. 100 Single-Particle States in 255Lr WS HFB Theory: 7/2+ 5/2- 0.5 1/2- 9/2+ 7/2- 0 Cwiok et al., NPA 573 (1994) 356 Bender et al., NPA 723 (2003) 354 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

5. The GREAT Spectrometer • UK Universities + Daresbury • 2 x 60mm x 40mm DSSD • 28 x 28mm x 28mm PIN Diodes • 24 x 12 Segmented Planar Ge • Compton-Suppressed Segmented Ge Clover • Position-Sensitive MWPC • Total Data Readout (TDR) Acquisiton System Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

6. Alpha Decay of 255Lr – JYFL data P. T. Greenlees et al. preliminary data N.B. in-growth of 8.37 MeV peak No α-γ or α-ecoincidences Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

7. 251Md 7596 keV 7544 keV 235 keV 290 keV New states in 247Es 247Es Alpha Decay of 255Lr – GANIL data Strongest α line is not the g.s. to g.s. transition Ch. Theisen et al. preliminary data Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

8. Alpha Decay of 253No 48Ca + 207Pb σ  1.3 b F. P. Heßberger et al. (GSI) R.-D. Herzberg et al. (JYFL) Recoil-α-γ/CE measurements Ground state expected to be 9/2[734] Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

9. Alpha Decay of 253No – JYFL Expt.R.-D. Herzberg, J. Phys G30 (2004) R123 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

10. The SACRED Electron Spectrometer H. Kankaanpää et al., Accepted for publication in NIM A see also P.A. Butler et al., NIM A381 (1996) 433 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

11. CE spectra from 208Pb(22Ne,4n)226U H.Kankaanpää et al., Accepted for publication in NIM A R.D. Humphreys et al., PRC 69 (2004) 064234 226U level scheme: P.T. Greenlees et al., J. Phys. G 24 (1998) L63 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

12. Recoil-gated CE spectrum from 208Pb(48Ca,2n)254No P.A. Butler et al., PRL 89 (2002) 202501 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

13. The JUROGAM Ge Array 43 PhaseI and GASP-type detectors – Ex. EUROBALL and UK-France loan pool Efficiency ~ 4.2% @ 1.3 MeV TDR data acquisition system – Data rate ~ 5 MB/s @ 10 kHz Software BGO suppression Autofill system built by University of York, part of GREAT Project Online/Offline Sorting – Grain developed by P. Rahkila Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

14. Recoil-Gated Gamma-Ray Spectrum from 208Pb(48Ca,2n)254NoS.Eeckhaudt et al., JYFL – Poster 143 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

15. Singles Gamma-Ray Spectra from 204Hg(48Ca,2n)250Fm ”Online” Data! A. Pritchard, R.-D. Herzberg et al., University of Liverpool Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

16. Coincidence Gamma-Ray Spectra from 204Hg(48Ca,2n)250Fm A. Pritchard, R.-D. Herzberg et al., University of Liverpool ”Online” Data! Counts 467 (20+) Energy (keV) Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

17. gK ~ 0.7Mainly E2 7+2 [633] 7-2 [514] 7+ 2 7- 2 gK~1.3 MainlyM1 1-2 [521] Mainly E2 a ~ 0.9: gK ~ -0.55 1- 2 Electromagnetic Properties • Odd-proton orbitals in 251Md / 255Lr • B(M1)/B(E2) depends on (gK-gR)/Q0 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

18. Recoil-Gated Gamma-Ray Spectrum from 205Tl(48Ca,2n)251Md • Chatillon, Ch. Theisen et al., • CEA Saclay Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

19. Gamma-Gamma Coincidences 205Tl(48Ca,2n)251Md • Chatillon, Ch. Theisen et al., CEA Saclay Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

20. Dynamic Moments of Inertia J(2) J (2) (hbar2MeV-1) Rotational Frequency Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

21. Future Developments • Near Future: • In-beam spectroscopy of 253No and 255Lr with JuroGam + = SAGE • Combined In-beam electron and gamma spectroscopy • Liverpool/Daresbury/JYFL Collaboration • Digital Electronics Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

22. Collaborators: University of Liverpool, UK DAPNIA/SPhN CEA Saclay, France GSI Darmstadt, Germany IReS Strasbourg, France ANL Argonne, USA University of Helsinki, Finland University of Oslo, Norway Ludwig Maximilians Universität, Germany Niels Bohr Institute, Denmark Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

23. 250Fm Dynamic Moment of Inertia J(2) Theory: M. Bender et al., NPA 723 (2003) 354 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

24. 251Md Dynamic Moment of Inertia J(2) Theory: M. Bender et al., NPA 723 (2003) 354 Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

25. Cf Isotopes: Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

26. Cm Isotopes: Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

27. Fm Isotopes: Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

28. Gamma-Gamma Coincidences 208Pb(48Ca,2n)254No S. Eeckhaudt et al., JYFL Counts 498 20+ 537 (22+) Energy (keV) Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04