<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Ni</mml:mi></mml:mrow><mml:mprescripts /><mml:mrow /><mml:mrow><mml:mn>64</mml:mn></mml:mrow><mml:mrow /><mml:mrow /></mml:mmultiscripts></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mo>+</mml:mo></mml:mrow><mml:mrow><mml:mn>92</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>Zr f

Wolfs, F. L. H.; Janssens, R. V. F.; Holzmann, R.; Khoo, T. L.; C., W.; Sanders, S.

doi:10.1103/physrevc.39.865

Cited by 22 publications

(11 citation statements)

References 17 publications

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“…With our approach, the average deviations of 92% systems in χ 2 log are less than 0.05, which indicates that this approach is successful for describing fusion cross sections of heavy-ion reactions at energies near and above the barrier from light to intermediate-heavy fusion systems. In Fig.3 [22], in which the solid and dashed curves present the results of our approach and of ref. [2], respectively, the squares denote the experimental data.…”

Section: Calculated Results For Fusion (Capture) Excitation Funcmentioning

confidence: 89%

Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

Wang

et al. 2006

Phys. Rev. C

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The Skyrme energy-density functional approach has been extended to study the massive heavyion fusion reactions. Based on the potential barrier obtained and the parameterized barrier distribution the fusion (capture) excitation functions of a lot of heavy-ion fusion reactions are studied systematically. The average deviations of fusion cross sections at energies near and above the barriers from experimental data are less than 0.05 for 92% of 76 fusion reactions with Z 1 Z 2 < 1200.For the massive fusion reactions, for example, the 238 U-induced reactions and 48 Ca+ 208 Pb the capture excitation functions have been reproduced remarkable well. The influence of structure effects in the reaction partners on the capture cross sections are studied with our parameterized barrier distribution. Through comparing the reactions induced by double-magic nucleus 48 Ca and by 32 S and 35 Cl, the 'threshold-like' behavior in the capture excitation function for 48 Ca induced reactions is explored and an optimal balance between the capture cross section and the excitation energy of the compound nucleus is studied. Finally, the fusion reactions with 36 S, 37 Cl, 48 Ca and 50 Ti bombarding on 248 Cm, 247,249 Bk, 250,252,254 Cf and 252,254 Es, and as well as the reactions lead to the same compound nucleus with Z = 120 and N = 182 are studied further. The calculation results for these reactions are useful for searching for the optimal fusion configuration and suitable incident energy in the synthesis of superheavy nuclei. * Electronic address: Ning.Wang@theo.physik.uni-giessen.de

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Section: Calculated Results For Fusion (Capture) Excitation Funcmentioning

confidence: 89%

Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

Wang

et al. 2006

Phys. Rev. C

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“…We first consider the Ni + ' Mo system. EvAp calculations and recent experiments on a similar system [13] indicate that the fission cross section is no more than 1/11th of the residue cross section. On the other hand, the strongly damped cross section may be as large as the residue cross section.…”

Section: Relative Yield Suppressionmentioning

confidence: 79%

Dynamics of heavy-ion fusion probed byd/pdouble ratios from a cross bombardment

Korolija

et al. 1995

Phys. Rev. C

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The particle decay ensuing from the reactions 86.0 MeV ' 0 + ' Sm and 239.1 MeV Ni + 'Mo was studied. These reactions each form ' Yb compound nuclei excited to = 54 MeV. Particle decay from compound nucleus producing reactions was selected by gating on the gamma-ray fold and the angular region of the particle emission. While there are no discernable differences in the dominant decay channels between the two reactions, there are fewer deuterons from the more symmetric system. This difference can be interpreted two ways: as a suppression of the emission of energetically expensive clusters during the time required for shape equilibration (which is predicted to be longer for the more symmetric entrance channel), or as an enhancement of the emission of energetically expensive clusters from the more asymmetric system at the very early stage of the collision when the initial energy deposited is only available to a reduced number of nucleons. The first explanation is identical to that used in recent high energy photon work while the second could be identified as the result of the emission of clusters on the multistep compound branch leading to the fusion of the low energy heavy ions. If the first explanation is adopted, the observed suppression is larger than predicted by a standard statistical decay model coupled to a dynamical fusion model, but consistent with work using high energy photons as a probe of fusion dynamics.

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“…The escape rate across the potential barrier or the fission rate was obtained by Kramers [100] many years ago. A reduction in fission width is obtained from the dissipative stochastic dynamical model of fission developed by Kramers where the fission width is given as [100] Kram f (E * , , K ) 64 Ni + 92 Zr [30,31], 12 C + 158 Gd [32,33], 16 O + 154 Sm [17,32,[34][35][36], 20 Ne + 150 Nd [33,[37][38][39], and 4 He + 188 Os [40][41][42]. Neutron multiplicities of 12 where β is the reduced dissipation coefficient (ratio of dissipation coefficient to inertia) and ω s is the local frequency of a harmonic oscillator potential which approximates the nuclear potential at the saddle configuration and depends on the spin of the CN [101].…”

Section: A the Modelmentioning

confidence: 99%

Detailed statistical model analysis of observables from fusion-fission reactions

2019

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Background:Despite remarkable success of the statistical model (SM) in describing decay of excited compound nuclei (CN), reproduction of the observables from heavy ion-induced fusion-fission reactions is often quite challenging. Ambiguities in choosing the input parameters, lack of clarity about inclusion of various physical effects in the model, and contradictory requirements of input parameters while describing different observables from similar reactions are among the major difficulties of modeling decay of fissile CN. Purpose: This work attempts to overcome the existing inconsistencies by inclusion of important physical effects in the model and through a systematic analysis of a large set of data over a wide range of CN mass (A CN ). Method: The model includes the shell effect in the level density (LD) parameter, shell correction in the fission barrier (B f ), the effect of the orientation degree of freedom of the CN spin (K or ), collective enhancement of level density (CELD), and dissipation in fission. Input parameters are not tuned to reproduce observables from specific reaction(s) and the reduced dissipation coefficient (β) is treated as the only adjustable parameter. Calculated evaporation residue (ER) cross sections (σ ER ), fission cross sections (σ fiss ), and particle, i.e., neutron, proton, and α particle, multiplicities are compared with data covering A CN = 156-248. Results: The model produces reasonable fits to ER and fission excitation functions for all the reactions considered in this work. Pre-scission neutron multiplicities (ν pre ) are underestimated by the calculation beyond A CN ∼ 200. An increasingly higher value of β, in the range of 2-4 × 10 21 s −1 , is required to reproduce the data with increasing A CN . Proton and α-particle multiplicities, measured in coincidence with both ERs and fission fragments, are in qualitative agreement with model predictions. Conclusions:The present work mitigates the existing inconsistencies in modeling statistical decay of the fissile CN to a large extent. Contradictory requirements of fission enhancement-obtained by scaling down the fission barrier to reproduce σ ER or σ fiss and fission suppression realized by introducing dissipation in the fission channel to reproduce ν pre , for similar reactions-have now become redundant. There are scopes for further refinement of the model, as is evident from the mismatch between measured and calculated particle multiplicities in a few cases.

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Ni64+92Zr f

Cited by 22 publications

References 17 publications

Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

Applications of Skyrme energy-density functional to fusion reactions for synthesis of superheavy nuclei

Dynamics of heavy-ion fusion probed byd/pdouble ratios from a cross bombardment

Detailed statistical model analysis of observables from fusion-fission reactions

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