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252,253,254No

250Fm

Spectroscopy of the heaviest

Nuclei

Overview

• Transfermium Nuclei

• Internal Conversion

• In-beam g and CE spectroscopy:253No

• The SAGE Spectrometer

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Shell Positions for 298114

From M. Bender et al., PRC 60 (1999) 034304

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Deformed orbitals

Problems:

No gap at Z=100 or 102

No gap at N=152

Trace to position of high-j

Orbitals?

p i13/2 n j15/2

M Bender, e.g. in

A. Chatillon et al, EPJA30, 06, 397

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Different Skyrme Forces

Nuclear EOS from

18 different Skyrme

parametrisations

All agree around

nuclear density

S. Typel, B.A. Brown,

PRC 64 027302.

Neutron density

r0 = 0.16 fm-3

Today

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RDH & PTG, Prog Part Nucl Phys 61 (2008) 674

Experimental Tools

• Decay spectroscopy

• In-beam spectroscopyc.f. Eddie Parr talk today

– Gamma Rays

– Conversion Electrons

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Systematics Z=99: Es

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F.P. Hessberger et al., EPJA 26 (2005) 233

Single particle Z=99

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7/2+ ? 3/2- ?

Neutrons e.g. N=149

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c.f. TASIspec

Poster LL Andersson

Experimental Tools

• Decay spectroscopy

• In-beam spectroscopyc.f. Eddie Parr talk today

– Gamma Rays

– Conversion Electrons

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Internal Conversion

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Electron Wavefunction

Spectrum

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Conversion Coefficients

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Z=100

a = 1

e- dominate

g dominate

M1

K

E2

K

alp

ha

103

102

10

1

0.1

10-2

100 200 300 400 500

Conversion Coefficients

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0

5

10

15

20

25

30

tot K L1 L2 L3 M

E1

M1

E2

M2

E3

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

K L1 L2 L3 M

Absolute Normalised

E = 200 keV Z= 102 BrICC (T. Kibédi et al., NIMA 589 (2008) 202)

Advantages of ICE

• Multipolarity and Parity directly

observable from subshell ratios

• Mixing ratios directly accessible

• Low energy transitions observable

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253No: 151 neutrons

• Ground state 9/2-

• Excited state 7/2+

Rotational band

observed at

Gammasphere,

assigned 7/2+

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R. Chasman et al, Rev Mod Phys 49 (1977) 833.

9/2-[734]

7/2+[624]

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253No Gammasphere

P. Reiter, PRL 95 (05) 032501

253No Jurogam

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M1

11400 Recoils

Levelscheme

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EPJA submitted

S. Moon, PhD thesis

SACRED Data

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1840(40) Recoils

T. Page, PhD thesis

Moment of Inertia

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M. Bender et al.,

Skyrme-HFB

priv. comm.

Conclusions

• Observed band is built on g.s. 9/2-[734]

• Branching ratios were key

• Electron Spectroscopy is possible

• No band built on 7/2+ observed (yet)

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SAGE

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S(ilicon) A(nd) GE(rmanium) spectrometer

RITU GREATJUROGAM II

Si detector

Fully instrumented with digital electronics

Beam

Clovers

Phase I

SAGE and JUROGAM II

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SAGE

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Beam

Ge opening

angles

Shielding

Photomultiplier

tubes are sensitive

to magnetic fields

Shields: Weaken

& redirect stray

magnetic field

B[T]

Capability

• 106 Chn Ge @ 30-50 kHz

• 90 Chn Si @ 30-50 kHz

• Triggerless TDR DAQ

– no common dead time!

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Digital Electronics

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10 kHz

20 kHz

30 kHz

40 kHz

50 kHz

Early implementation – still needs pileup and Compton Suppression

Experiments

• SHE:

• 253No, 251Md, 255Lr, …

• 254No, 256Rf, …

• Shape Coexistence:

• 184-190Pb, 180-188Hg, light Po,Bi etc…

• E0 from multiphonon states

• EtcR-D Herzberg

SAGE

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Status April 2nd

Philippos Juha Janne

Summary

• Combined Electron and Gamma Ray

spectroscopy is a very powerful tool

• The SAGE Spectrometer will be

commissioned in the summer

• Experiments welcome in the

September PAC!

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SAGE Collaboration

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University of Liverpool, UK

R.-D. Herzberg, J. Pakarinen, P. Papadakis,

L.L. Andersson, P.A. Butler, R.D. Page,

J.R. Cresswell, D.A. Seddon, J. Thornhill,

D. Wells

University of Jyväskylä, Finland

P.T. Greenlees, P. Jones, R. Julin,

P. Rahkila, J. Sorri

STFC Daresbury Laboratory, UK

J. Simpson, P.J. Coleman-Smith,

I.H. Lazarus, S.C. Letts, V.F.E. Pucknell