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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. - PowerPoint PPT Presentation
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Experimental Nuclear Physicsin ATOMKI Debrecen
Cyclotron laboratory in ATOMKI, Debrecen
The split-pole magnetic spectrometer in ATOMKI
Experimental setup for studying fission (transmission) resonances
Results for 236U
P.G. Goldstone et al., PRC 18 (1978) 1706A. Krasznahorkay et al., PRL 80
(1998) 2073
On the depth of the third minimum
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
Cold fission
Compact fission
A=100 A=132
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 Use of the DIAMANTDIAMANT ancillary detector ancillary detector in studying extreme nuclear shapes at in studying extreme nuclear shapes at
large angular momentalarge angular momenta
C.E.N.B.G. (Bordeaux) and ATOMKI (Debrecen) (2000-present)
DIAMANT DIAMANT in search for hyperdeformation 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!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 (
2,) 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.
Different other gamma spectroscopy experiments in Legnaro
Collaboration with GANIL, France
Giant resonance studies
Beams from AGOR at KVI GroningenBeams from Ring Cyclotron
at RCNP Osaka
Big Bite magnetic Spectrometer (BBS)
Coincidence measurements with Coincidence measurements with the BBSthe BBS
Results for the neutron-skin thicknesses
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, ...)
-ray spectroscopy, isospin-dependence in multifragmentation
The high-energy branch of the Super-FRS:
A versatile setup for kinematical complete measurements of
Reactions with Relativistic Radioactive Beams
Exotic beam from Super-FRS
Target
Large-acceptance measurement
High-resolution measurement