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