Horizontal Evaluation (Topical Review) on K-Isomers in Deformed Nuclei Filip G. Kondev 17 th NSDD...
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Horizontal Evaluation (Topical Review) on K-Isomers in Deformed Nuclei Filip G. Filip G. Kondev Kondev 17 th NSDD Network meeting, St. Petersburg, Russia, 2007 Nuclear Engineering Division Nuclear Engineering Division Outline Introduction & Motivation (very brief!) Present Status & Outlook [email protected] v
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Transcript of Horizontal Evaluation (Topical Review) on K-Isomers in Deformed Nuclei Filip G. Kondev 17 th NSDD...
Horizontal Evaluation (Topical Review) on K-Isomers in Deformed Nuclei
Filip G. KondevFilip G. Kondev
17th NSDD Network meeting, St. Petersburg, Russia, 2007
Nuclear Engineering DivisionNuclear Engineering Division
Outline
Introduction & Motivation (very brief!)
Present Status & Outlook
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Introduction & Motivation
Potential for many applications:Astrophysics, Activation analysis; Medicine; Detector calibration standards; Nuclear energy
KKii
j
j
j
KKff=0=0long-lived states due to conservation of the K quantum number
Probe various aspects of nuclear structure at extreme conditions:
interplay between intrinsic & collective motion limits of conservation of K-quantum number (robustness of symmetry) seniority dependence of major residual interactions in deformed nuclei
Exotic nuclear structure studies: radioactive targets – high-spin/seniority – e.g. 178mHf, 177mLu radioactive beams – the future – physics at extreme conditions
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Deformed nuclei with axially-symmetric shape
High-K orbitals near the Fermi surface 5/2[402], 7/2[404], 9/2[514]
5/2[512], 7/2[514], 7/2[633], 9/2[624]
K Isomers: Where to find them?
Mass 180 region : Yb (Z=70)-Ir(Z=77)Mass 180 region : Yb (Z=70)-Ir(Z=77)
KK
j
j
j
7-qp
K=49/2
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The Best Known Isomer …
Jag has been always in an
excited state!
he will have a
very long lifetime!
and
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Isomers Research at Argonne
Availability of a variety of HI beams and a flexible beam pulsing system
from 4He up to 238U/ time-range from ns up to years!
Existence of high-efficiency detector systems, e.g. Gammasphere & FMAStudying Isomers at extreme conditions:
Heavy nuclei/ Proton Drip Line/ Neutron Rich Nuclei/High-spin & Seniority
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K-Isomers Evaluation Aim – to evaluate properties of all K-isomers in deformed nuclei – including Ex, K, J, T1/2, BR, ICC, B(XL) and f - no such systematic study exists, but it is very much needed!
Why not using ENSDF directly?
we (in ENSDF) don’t treat explicitly the K-quantum number long updating time (6-8 years)
E(X)
(I,Ki
(I,Kf
=K- – degree of K-forbiddennessF=(X)/w(X) – hindrance factor
f=(F)1/ – reduced hindrance per degree of K-forbiddenness – gives yardstick for “goodness” of the K-quantum number
20< f<100K-hindered decay
f<10 - anomalous decay
fv>100 – perhaps something is wrong!
for M1 and E2 decays
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K-Isomers Evaluation-cont.
The data are evaluated in ENSDF format
have agreed on general policies – tried to follow the ENSDF policies as much as possible
specialized codes were developed
The evaluation will be completed in the next 1-2 years and it will be made available to all NSDD centers and published
can easily be used to update ENSDF will make specific recommendations to improve ENSDF – introduction of the K-quantum number explicitly
it will be continuously updated
the need to include other classes of isomers – will depend on the needs of the community
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Prediction of energies, J – OK: WS (Nilsson) with pairing Prediction of T1/2? – not so good!
K-Isomers Evaluation-cont.
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Collaborators
Supported by the Office of Nuclear Physics, U.S. DOE
T. Kibedi & G.D. Dracoulis Australian National University, Canberra, Australia
Encouragement and advice from many colleagues:
R. Janssens (ANL), P. Chowdhury (UML), P. Walker (U. Surrey), and others
