NUCLEAR THEORY @ INP - NCSR D Nuclear Structure Staff: Dennis Bonatsos Students: P. Georgoudis S....
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Transcript of NUCLEAR THEORY @ INP - NCSR D Nuclear Structure Staff: Dennis Bonatsos Students: P. Georgoudis S....
NUCLEAR THEORY @ INP - NCSR D
Nuclear Structure
Staff:
Dennis Bonatsos
Students:
P. Georgoudis
S. Karabatsou
Collaborations:
N. Minkov, P.A. Terziev, INRNE Sofia
D, Balabanski, U. Sofia
M.N. Erduran, B. Akkus, Istanbul U.
N. Casten, Yale U., N. Pietralla SUNY at Stony Brook
Nuclear Reactions & Astrophysics
Staff:
Vivian Demetriou (since 2006)
Post-doctoral researcher:
D. Petrellis
Collaborations: Nuclear Physics Exp. group
S. Goriely, ULB, Brussels
Y. El Masri, UCL, LLN
Vivian Demetriou, INP, NCSR Demokritos
NUCLEAR THEORY @ INP - NCSR D
Nuclear Structure
Conferences/Workshops:
International Balkan School on Nuclear Physics, 1998-2010
Symposium of the Hellenic Nuclear Physics Society
Workshop on Dynamical Symmetries 2008
Nuclear Reactions & Astrophysics
Support: European Reintegration Grant (2005) on Alpha-nucleus OP
Conferences/Workshops:
FINUSTAR (2005), FINUSTAR 2 (2007), FINUSTAR 3 (2010)
LIBRA project 2009-2011
• Nuclear structure:
study of dynamical symmetries
experiment-theory
• Nuclear Astrophysics
development of alpha-particle optical potential
alpha-capture measurements
theory post-doc position open for 2011
Collaborations
INRNE, Sofia, Bulgaria: N. Minkov, P. A. Terziev.U. Sofia, Bulgaria / U. Camerino, Italy : D. Balabanski. Istanbul U., Turkey: M. N. Erduran, B. Akkus. SUNY at Stony Brook, USA: N. Pietralla
Support: Collaborative Linkage Grant (6/2002-6/2004). New dynamic symmetries in atomic nuclei. Istanbul U. (M. N. Erduran), Bogazici U. (M. Arik), U. Sofia (D. Balabanski), NIPNE Bucharest (M. Ionescu-Bujor), NCSR Demokritos (D. Bonatsos), Yale U. (R. F. Casten).
Nuclear Structure:
CRITICAL POINT SYMMETRIES (2003-present)
Topics:
- Sequences of potentials interpolating between U(5) and E(5) or X(5). - Davidson potentials, variational procedure. - Z(5): Solution of Bohr equation for gamma=30 deg. - Transition to octupole deformation in light actinides. - Wobbling motion within X(5). - Triaxial shapes. - Comparison between Davidson and displaced well potentials. - Derivation of collective models from rotation invariant potentials through Goldstone bosons and the Higgs mechanism. - Search for larger symmetries which could lead to X(5) through contraction.
Nuclear Reactions & Astrophysics
nuclear reactions relevant to heavy-element nucleosynthesis
provide cross sections and reaction rates for reaction network calculations (TALYS code)
develop global and microscopic models for nuclear properties
Nuclear needs for nucleosynthesis applications
Exotic species (no experimental data)
Astrophysics conditions (proj. energy or target conditions not available in the Lab.)
• Ground state mass, deformation, density distribution, single-particle-level scheme, … • Nuclear Level Densities• Fission properties: fission barriers and saddle-point NLDs• Nucleon- and alpha-nucleus optical potential • γ-strength function: Giant Resonance Properties
Nuclear properties for cross section calculations
Nuclear Ingredients from (1) direct experimental data(2) theoretical models
…For about 8000 nuclei….from dripline to dripline
r process: Fission
Fission paths microscopic HFB shapes
(Hill-Wheeler) and WKB penetrabilities
uncertainties : B 1 MeV T 104
Spontaneous fission T1/2
n-induced fission
β-delayed fission
Q
PD, Samyn, Goriely, NPA 758 (2005),627c;Goriely, PD et al., NPA 758 (2005), 587c
Work in progress: same HFB model for masses, NLDs and fission
r: ratio of maximum over minimum rates obtained with 14 different sets of nuclear ingredients using MOST
Arnould and Goriely, Phys. Rep. 384, 1 (2003)
neutron captures
proton captures
α captures
p-process nucleosynthesis: n-, p- and alpha captures
αlpha radiative-capture rates
•low-energy cross sections depend on α-nucleus optical model potential•poor knowledge of α-nucleus optical potential at energies close to Coulomb barrier•optical potential determined from scattering and reaction data•data at low energies are SCARCE
- Square-well potential +− −−
- Woods-Saxon ++ +−
- Double-folded real + W-S ++ ++ (semi-microscopic: new global OMP)
accuracy reliability
• Semi-microscopic alpha OP (PD, Grama and Goriely NPA 707 (2002) 253)
INP Exp. Group measurements
predictions
mass regions with largest uncertainties
Work in progress...and Future
Update existing semi-microscopic alpha OP on new data
Develop fully microscopic alpha OP with RPA
in close collaboration with INP Experimental Nuclear Physics group
target nuclei in (α,) reactions studied via a 4π summing method