Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

In-beam and decay spectroscopy of transfermium elements

251Md

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

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

Single-Particle States in 255Lr

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

Theory:

100

7/2-

5/2-

7/2+

9/2+1/2-

0

0.5

WS HFB

Cwiok et al.,

NPA 573 (1994) 356

Bender et al.,

NPA 723 (2003) 354

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

Alpha Decay of 255Lr – JYFL data

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

P. T. Greenlees et al. preliminary data

N.B. in-growth of 8.37 MeV peak

No α-γ or α-e coincidences

Alpha Decay of 255Lr – GANIL data

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

Ch. Theisen et al.preliminary data

New states in 247EsStrongest α line is not

the g.s. to g.s. transition

290 keV

247Es

251Md

7544 keV

235 keV

7596 keV

Alpha Decay of 253No

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

48Ca + 207Pb σ 1.3 bF. P. Heßberger et al. (GSI)R.-D. Herzberg et al. (JYFL)

Ground state expected to be 9/2[734]

Recoil-α-γ/CE measurements

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

The SACRED Electron Spectrometer

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

H. Kankaanpää et al., Accepted for publication in NIM A

see also P.A. Butler et al., NIM A381 (1996) 433

ENAM’04, Callaway Gardens, Sept04

CE spectra from 208Pb(22Ne,4n)226U

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

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

ENAM’04, Callaway Gardens, Sept04

Recoil-gated CE spectrum from 208Pb(48Ca,2n)254No

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

P.A. Butler et al.,

PRL 89 (2002) 202501

ENAM’04, Callaway Gardens, Sept04

The JUROGAM Ge Array

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

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

ENAM’04, Callaway Gardens, Sept04

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

Singles Gamma-Ray Spectra from 204Hg(48Ca,2n)250Fm

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

A. Pritchard, R.-D. Herzberg et al., University of Liverpool ”Online” Data!

ENAM’04, Callaway Gardens, Sept04

Coincidence Gamma-Ray Spectra from 204Hg(48Ca,2n)250Fm

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

A. Pritchard, R.-D. Herzberg et al., University of Liverpool

”Online” Data!

Energy (keV)

Cou

nts

467

(20+

)ENAM’04, Callaway Gardens, Sept04

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

gK ~ 0.7 Mainly E2[514] 7-

2

7 -

2

7 +

2

[633] 7+

2gK ~ 1.3 Mainly M1

1 -

2

[521] 1-

2a ~ 0.9:

gK ~ -0.55

Mainly E2

ENAM’04, Callaway Gardens, Sept04

Recoil-Gated Gamma-Ray Spectrum from 205Tl(48Ca,2n)251Md

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

A. Chatillon, Ch. Theisen et al.,

CEA Saclay

ENAM’04, Callaway Gardens, Sept04

Gamma-Gamma Coincidences 205Tl(48Ca,2n)251Md

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

A. Chatillon, Ch. Theisen et al., CEA Saclay

ENAM’04, Callaway Gardens, Sept04

Dynamic Moments of Inertia J(2)

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

J (2

) (h

bar

2 MeV

-1)

Rotational Frequency

ENAM’04, Callaway Gardens, Sept04

Future Developments

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

+ = SAGE

•Combined In-beam electron and gamma spectroscopy

•Liverpool/Daresbury/JYFL Collaboration

•Digital Electronics

Near Future:

•In-beam spectroscopy of 253No and 255Lr with JuroGam

ENAM’04, Callaway Gardens, Sept04

Collaborators:

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

University of Liverpool, UKDAPNIA/SPhN CEA Saclay, FranceGSI Darmstadt, GermanyIReS Strasbourg, FranceANL Argonne, USA University of Helsinki, FinlandUniversity of Oslo, NorwayLudwig Maximilians Universität, GermanyNiels Bohr Institute, Denmark

ENAM’04, Callaway Gardens, Sept04

250Fm Dynamic Moment of Inertia J(2)

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

Theory:

M. Bender et al., NPA 723 (2003) 354

ENAM’04, Callaway Gardens, Sept04

251Md Dynamic Moment of Inertia J(2)

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

Theory:

M. Bender et al., NPA 723 (2003) 354

ENAM’04, Callaway Gardens, Sept04

Cf Isotopes:

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

Cm Isotopes:

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

Fm Isotopes:

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland ENAM’04, Callaway Gardens, Sept04

Gamma-Gamma Coincidences 208Pb(48Ca,2n)254No

Paul Greenlees, Department of Physics, University of Jyväskylä, Finland

S. Eeckhaudt et al., JYFLC

oun

ts

Energy (keV)

537

(22+

)

498

20+

ENAM’04, Callaway Gardens, Sept04