Interplay of mean field and individual nucleon collisions effects at intermediate energy heavy ion reactions

In our study of the reaction Ne-20+Al-27 at energy of 84 A MeV, the track detectors were used to select the target like fragments arising from processes in which the interacting system becomes disintegrated into a large number of constituent nucleons and one massive fragment. Heavy ion reaction studies at bombarding energies of several tens of MeV/nucleon have provided the evidence that most of reaction cross section, in this energy range, is associated with the production of primary projectile like and target like fragment in the first step of the nuclear reaction. The subsequent evolution of the studied reaction systems, has been usually described either using low energy models based on mean field effects (WE), or high energy models where reaction proceeds by independent collisions (INC) of individual nucleons in the overlap region between target and projectile. The analysis of our results in terms of different MFE and INC models, prescribing consistent timings, has shown that the reaction mechanism may be defined of interplay of the mean field and individual nucleon collisions effects.6th International Conference of the Balkan-Physical-Union, Aug 22-26, 2006, Istanbul, Turke

On the border between low-nuclearity and one-dimensional solids : a unique interplay of 1,2,4-triazolyl-based {CuII5(OH)2}\{{Cu^{II}}_{5}(OH)_2\} clusters and MoVIMo^{VI}-oxide matrix

A pentanuclear CuII5-hydroxo cluster possessing an unusual linear-shaped configuration was formed and crystallized under hydrothermal conditions as a result of the unique cooperation of bridging 1,2,4-triazole ligand (trans-1,4-cyclohexanediyl-4,4′-bi(1,2,4-triazole) (tr2cy)), MoVI-oxide, and CuSO4. This structural motif can be rationalized by assuming in situ generation of {Cu2Mo6O22}4– anions, which represent heteroleptic derivatives of γ-type [Mo8O26]4– further interlinked by [Cu3(OH)2]4+ cations through [N−N] bridges. The framework structure of the resulting compound [Cu5(OH)2(tr2cy)2Mo6O22]·6H2O (1) is thus built up from neutral heterometallic {Cu5(OH)2Mo6O22}n layers pillared with tetradentate tr2cy. Quantum-chemical calculations demonstrate that the exclusive site of the parent γ-[Mo8O26]4– cluster into which CuII inserts corresponds with the site that has the lowest defect (“MoO2 vacancy”) formation energy, demonstrating how the local metal-polyoxomolybdate chemistry can express itself in the final crystal structure. Magnetic susceptibility measurements of 1 show strong antiferromagnetic coupling within the Cu5 chain with exchange parameters J1 = −500(40) K (−348(28) cm–1), J2 = −350(10) K (−243(7) cm–1) and g = 2.32(2), χ2 = 6.5 × 10–4. Periodic quantum-chemical calculations reproduce the antiferromagnetic character of 1 and connect it with an effective ligand-mediated spin coupling mechanism that comes about from the favorable structural arrangement between the Cu centers and the OH–, O2–, and tr2cy bridging ligands

On the Border between Low-Nuclearity and One-Dimensional Solids: A Unique Interplay of 1,2,4-Triazolyl-Based {Cu^II₅(OH)₂} Clusters and Mo^VI-Oxide Matrix

A pentanuclear Cu^II₅-hydroxo cluster possessing an unusual linear-shaped configuration was formed and crystallized under hydrothermal conditions as a result of the unique cooperation of bridging 1,2,4-triazole ligand (<i>trans</i>-1,4-cyclohexanediyl-4,4′-bi­(1,2,4-triazole) (<i>tr</i>₂<i>cy</i>)), Mo^VI-oxide, and CuSO₄. This structural motif can be rationalized by assuming <i>in situ</i> generation of {Cu₂Mo₆O₂₂}^4– anions, which represent heteroleptic derivatives of γ-type [Mo₈O₂₆]^4– further interlinked by [Cu₃(OH)₂]⁴⁺ cations through [<i>N</i>−<i>N</i>] bridges. The framework structure of the resulting compound [Cu₅(OH)₂(<i>tr</i>₂<i>cy</i>)₂Mo₆O₂₂]·6H₂O (<b>1</b>) is thus built up from neutral heterometallic {Cu₅(OH)₂Mo₆O₂₂}_<i>n</i> layers pillared with tetradentate <i>tr</i>₂<i>cy</i>. Quantum-chemical calculations demonstrate that the exclusive site of the parent γ-[Mo₈O₂₆]^4– cluster into which Cu^II inserts corresponds with the site that has the lowest defect (“MoO₂ vacancy”) formation energy, demonstrating how the local metal-polyoxomolybdate chemistry can express itself in the final crystal structure. Magnetic susceptibility measurements of <b>1</b> show strong antiferromagnetic coupling within the Cu₅ chain with exchange parameters <i>J</i>₁ = −500(40) K (−348(28) cm^–1), <i>J</i>₂ = −350(10) K (−243(7) cm^–1) and <i>g</i> = 2.32(2), χ² = 6.5 × 10^–4. Periodic quantum-chemical calculations reproduce the antiferromagnetic character of <b>1</b> and connect it with an effective ligand-mediated spin coupling mechanism that comes about from the favorable structural arrangement between the Cu centers and the OH^–, O^2–, and <i>tr</i>₂<i>cy</i> bridging ligands

Production of medium-mass neutron-rich nuclei in U-238 fission

The production cross sections of neutron-rich fission residues produced in reactions induced by a U-238 beam impinging onto Pb and Be targets were investigated at the Fragment Separator (FRS) at GSI. These data allowed us to discuss the optimum energies in fission for producing the most neutron-rich residues.4th International Workshop on Nuclear Fission and Fission-Product Spectroscopy, May 13-16, 2009, Cadarache, Franc

Exploring Nuclear Radii from Total Interaction Cross Sections of Medium Mass Nuclei

Experiments with radioactive nuclear beams have enabled us to investigate nuclear properties far from stability. Glauber model analysis of total interaction cross sections measurements provides a useful method to determine effective matter radii. In this work we have taken advantage of the relativistic heavy ion facility at GSI for producing and investigate total interaction cross sections of more than hundred medium-mass nuclei along long isotopic chains.International Conference on Nuclear Structure and Dynamics, May 04-08, 2009, Dubrovnik, Croati