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Experimental Nuclear Physics in ATOMKI Debrecen. Cyclotron laboratory in ATOMKI, Debrecen. The split-pole magnetic spectrometer in ATOMKI. Experimental setup for studying fission (transmission) resonances. R esults for 236 U. Krasznahorkay et al., PRL 80 (1998) 2073.
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Experimental setup for studying fission (transmission) resonances
Results for 236U • Krasznahorkay et al., PRL 80 • (1998) 2073 P.G. Goldstone et al., PRC 18 (1978) 1706
On the height of the fission barriers History of the 3. Minimum Möller … PLB 40 (1972) 329 Blons … PRL 41 (1978) 1282 (Howard, Möller, ADNDT 25 (1980) 218 ) Cwiok … PLB 322 (1994) 304
Clusterization A=100 A=132 Cold fission Compactfission
Collaborations Forshungszentrum Karlsruhe, Inst. f. Kernphysik
Nuclear Astrophysics at ATOMKI Main topics: • Underground nuclear physics (LUNA collaboration) • Ultra low energy collisions • Electron screening • Stopping power • Astrophysical p-process • Reaction rates • Optical potentials • Exotic nuclear physics • Resonance strength determinations • Half-life studies
Collaborations: • LUNA: Italy/Germany/Portugal/Hungary • Uni Bochum, Germany • Demokritos Inst. Greece • RIKEN, Japan • TU Darmstadt, Germany • Uni Basel, Switzerland • Notre Dame University, USA
Use of the DIAMANT ancillary detector in studying extreme nuclear shapes at large angular momenta C.E.N.B.G. (Bordeaux) and ATOMKI (Debrecen)(2000-present)
DIAMANT in search for hyperdeformation DIAMANT has been used in EUROBALL experiments aiming at, e.g., the identification of rotational structures characteristic for hyperdeformed (HD) shapes in nuclei 168-172Hf and 126Ba.Hotest subject of present-day gamma-spectroscopy! Which of these is more favorable? 1) 126Ba is predicted to be the best candidate for having stable HD structures: Theoretical predictions (macroscopic calculations by J. Dudek), indicate that the energy minimum (dark blue regions) of the 126Ba nucleus at deformations (b2,g) corresponding to hyperdeformed shapes remains stable upto very high spins (I). At a critical spin of I > 74 ħ the nucleus becomes unstable against fission.
Giant resonance studies Big Bite magnetic Spectrometer (BBS) Beams from AGOR at KVI Groningen Beams from Ring Cyclotron at RCNP Osaka
Coincidence measurements with the BBS Results for the neutron-skin thicknesses
The high-energy branch of the Super-FRS: A versatile setup for kinematical complete measurements of Reactions with Relativistic Radioactive Beams Large-acceptance measurement Exotic beam from Super-FRS Target High-resolution measurement Experiments • knockout and quasi-free scattering • electromagnetic excitation • charge-exchange reactions • fission • spallation • fragmentation Physics goals single-particle occupancies, spectral functions, correlations, clusters, resonances beyond the drip lines single-particle occupancies, astrophysical reactions (S factor), soft coherent modes, giant resonance strength, B(E2) Gamow-Teller strength, spin-dipole resonance, neutron skins shell structure, dynamical properties reaction mechanism, applications (waste transmutation, ...) g-ray spectroscopy, isospin-dependence in multifragmentation