Fast dissipative collisions

Petrovici, M.; Albinski, J.; Bock, R.; Cusson, R.Y.; Gobbi, A.; Guarino, G.; Gralla, Samuel E.; Hildenbrand, K. D.; Müller, W. F. J.; Olmi, A.; Stelzer, H.; Tōke, J.

doi:10.1016/0375-9474(88)90322-3

Cited by 14 publications

(10 citation statements)

References 26 publications

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“…Because these events have been discussed previously, their important features will be only summarized in this paper. For a more exhaustive discussion detailing the evolution with bombarding energy refer to [24,25].…”

Section: Two-body Eventsmentioning

confidence: 99%

Results on two-, three-, and four-body events from the100Mo+100Mo and120Sn+120Sn collisions aroundE/A=20 MeV

Charity¹,

Freifelder²,

Gobbi³

et al. 1991

Z. Physik A - Hadrons and Nuclei

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Events with 2, 3 and 4 heavy-fragments (A>20) have been detected in the reactions l~176 l~176 at E/A = 18.7, 23.7 MeV and 12~ t2~ at E/A= 18.4 MeV.The experiments were performed with an array of 12 detectors which together covered a large fraction of the forward hemisphere and allowed a high detection efficiency for these events. Masses and energies of all fragments have been reconstructed by means of an improved version of the kinematic coincidence method. The probabilities P~ and P4 of producing 3-and 4-body events were found to depend mainly on the dissipated energy rather than on the bombarding energy, thus indicating that their origin lies more in the decay properties of the excited fragments than in the dynamics of the interaction. Emission of light particles from the composite system is shown to become more relevant with increasing bombarding energy and may explain the drop of the P3 and P4 curves at high energy losses. Small deviations of the P3 and P4 curves at 23.7 A. MeV from those at lower bombarding energies were used to estimate the amount of a possible pre-equilibrium light particle emission as a function of impact parameter.

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Section: Two-body Eventsmentioning

confidence: 99%

Results on two-, three-, and four-body events from the100Mo+100Mo and120Sn+120Sn collisions aroundE/A=20 MeV

Charity¹,

Freifelder²,

Gobbi³

et al. 1991

Z. Physik A - Hadrons and Nuclei

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“…In such reactions, the N/Z degree of freedom (loosely called "isospin" degree of freedom) and its equilibration have prominent roles and can serve as valuable probes of the symmetry energy term of the nuclear equation of state [4,5]. Extensive work in deep-inelastic heavy-ion collisions at low energies (E/A<10 MeV, for a review see, e.g., [6,7]) provided insight into the relevant reaction mechanisms [8,9,10]. At these energies, the collisions are of binary character involving a transient dinuclear complex.…”

Section: Introductionmentioning

confidence: 99%

“…The N/Z of the residue is reminiscent of the N/Z of the corresponding hot primary fragment, but the former is substantially affected by the evaporation process. Efforts to reconstruct the primary quasiprojectile [9,10] based on evaporation codes provide a first picture of the process of N/Z equilibration as a function of the excitation energy and thus, the interaction time. It should be noted that information on N/Z equilibration has also been obtained recently in prompt γ-ray studies [18] in which enhanced emission of dipole γ rays during the N/Z equilibration process was observed in isospin asymmetric reactions.…”

Section: Introductionmentioning

confidence: 99%

Heavy-residue isoscaling as a probe of the process of N/Z equilibration

et al. 2004

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The isotopic and isobaric scaling behavior of the yield ratios of heavy projectile residues from the collisions of 25 MeV/nucleon 86 Kr projectiles on 124 Sn and 112 Sn targets is investigated and shown to provide information on the process of N/Z equilibration occurring between the projectile and the target. The logarithmic slopes α and β ′ of the residue yield ratios with respect to residue neutron number N and neutron excess N-Z are obtained as a function of the atomic number Z and mass number A, respectively, whereas excitation energies are deduced from velocities. The relation of the isoscaling parameters α and β ′ with the N/Z of the primary (excited) projectile fragments is employed to gain access to the degree of N/Z equilibration prior to fragmentation as a function of excitation energy. A monotonic relation between the N/Z difference of fragmenting quasiprojectiles and their excitation energy is obtained indicating that N/Z equilibrium is approached at the highest observed excitation energies. Simulations with a deep-inelastic transfer model are in overall agreement with the isoscaling conclusions. The present residue isoscaling approach to N/Z equilibration offers an attractive tool of isospin and reaction dynamics studies in collisions involving beams of stable or rare isotopes.

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“…Efforts to reconstruct the quasiprojectile [25,26] based on evaporation codes provided some information on the process of N/Z equilibration as a function of energy dissipation and thus, the interaction time. In our previous work at 25 MeV/nucleon [64], using an isoscaling approach, we obtained information on the process of N/Z equilibration for the reaction 86 Kr + 124,112 Sn as a function of the excitation energy of the quasiprojectile.…”

Section: And Ref Therein)mentioning

confidence: 99%

“…Extensive work in deep-inelastic heavy-ion collisions at low energies (E/A<10 MeV, for a review see, e.g., [22,23]) provided insight into the relevant reaction mechanisms [24][25][26][27][28][29]. At these energies, the collisions are of binary character involving a transient dinuclear complex.…”

Section: Introductionmentioning

confidence: 99%

Isoscaling of heavy projectile residues andN/Zequilibration in peripheral heavy-ion collisions below the Fermi energy

et al. 2014

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The isoscaling of heavy projectile residues from peripheral heavy-ion reactions at 15-25 MeV/nucleon is employed to obtain information on the process of N/Z equilibration. Recent mass spectrometric data of projectile residues from the reactions of 86 Kr (15 MeV/nucleon) with 64,58 Ni and 124,112 Sn were first analyzed. The isotopically resolved yield distributions of the fragments in the range Z=26-39 were employed for the isoscaling analysis. The yield ratios R21(N,Z) of the fragments from each pair of systems exhibit isoscaling (i.e. an exponential dependence on the fragment neutron number N for each atomic number Z) with the isoscaling parameter α increasing with decreasing (or increasing) Z away from the projectile. This variation is related to the evolution toward N/Z equilibration with increasing energy dissipation estimated from the residue velocities. In parallel to the new heavy-residue isoscaling data of 86 Kr at 15 MeV/nucleon, our previous data at 25 MeV/nucleon for the reactions 86 Kr+ 124,112 Sn and 64 Ni+ 64,58 Ni, 64 Ni+ 124,112 Sn, as well as our data at 15 MeV/nucleon of the lighter system 40 Ar+ 64,58 Ni were analyzed in a similar way. Calculations with the stochastic nucleon-exchange model DIT (Deep Inelastic Transfer) and the microscopic many-body model CoMD (Constrained Molecular Dynamics) provided an overall fair description of data and valuable guidance for their interpretation. Interestingly, the data of the 86 Kr+Ni,Sn reactions at 15 MeV/nucleon show a retardation of the process of N/Z equilibration which, as suggested by the CoMD calculations, is indicative of the collective character of the process. This retardation is not present in the investigated systems at 25 MeV/nucleon (and the light 40 Ar+Ni systems at 15 MeV/nucleon), whose behavior is found to be consistent with stochastic nucleon exchange.

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Fast dissipative collisions

Cited by 14 publications

References 26 publications

Results on two-, three-, and four-body events from the100Mo+100Mo and120Sn+120Sn collisions aroundE/A=20 MeV

Results on two-, three-, and four-body events from the100Mo+100Mo and120Sn+120Sn collisions aroundE/A=20 MeV

Heavy-residue isoscaling as a probe of the process of N/Z equilibration

Isoscaling of heavy projectile residues andN/Zequilibration in peripheral heavy-ion collisions below the Fermi energy

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