6,7Li +28Si total reaction cross sections at near barrier energies

Pakou, A.; Musumarra, A.; Pierroutsakou, D.; Alamanos, N.; Assimakopoulos, P.A.; Divis, N.; Doukelis, G.; Gillibert, A.; Harissopulos, S.; Kalyva, G.; Kokkoris, M.; Lagoyannis, A.; Mertzimekis, T. J.; Nicolis, N. G.; Papachristodoulou, C.; Perdikakis, G.; Roubos, D.; Rusek, K.; Spyrou, S. M.; Zarkadas, Ch.

doi:10.1016/j.nuclphysa.2006.12.007

Cited by 21 publications

(26 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Especially, the processes induced by 6 Li and 7 Li nuclei gained attention due to the break-up effect of 6 Li into d + α, and 7 Li into t + α which plays a crucial role in the elastic scattering of 6 Li and 7 Li, for a range of target nuclei at different energies. There are extensive experimental measurements and theoretical studies for 6 Li + 28 Si nuclear system, and the available data are classified into two categories: experimental data near the Coulomb barrier energy EC [1][2][3][4][5][6][7] and the data above EC [8][9][10][11][12][13][14]. It is appropriate here to disregard particular effects due to coupling to other reaction channels when studying the elastic scattering mechanisms between two ions at energies well above the EC.…”

Section: Introductionmentioning

confidence: 99%

Cluster folding optical potential analysis for 6Li+28Si elastic scattering

Hamada

Ibraheem

2021

Rev. Mex. Fís.

View full text Add to dashboard Cite

Available experimental angular distribution data for 6Li+28Si elastic scattering in the energy range 16 – 318 MeV are re-analyzed phenomenologically on the basis of optical model using Woods-Saxon (WS) potentials for both real and imaginary parts, while the semi microscopic analysis was performed on the basis of cluster folding potential. Cluster folding potential was generated based on the appreciable cluster structure and breakup of 6Li into a deuteron orbiting a core of α-particle. Although several data sets in a wide range of energies are subjected to investigation, the theoretical calculations using the different concerned potentials are fairly reproduced the experimental data in the whole energy range. The extracted real and imaginary volume integrals and reaction cross sections values are compared to the previously reported ones and they found to be in a good agreement

show abstract

Section: Introductionmentioning

confidence: 99%

Cluster folding optical potential analysis for 6Li+28Si elastic scattering

Hamada

Ibraheem

2021

Rev. Mex. Fís.

View full text Add to dashboard Cite

show abstract

“…That is, direct reactions dominate over fusion ones, particularly as the energy approaches the barrier energy V B . As claimed by Pakou et al [4][5][6][7][8], direct reactions are not just breakup processes, but also transfer channels, which may even be more important than breakup at some energies for these systems.…”

mentioning

confidence: 92%

“…This new phenomenon has been termed the breakup threshold anomaly (BTA) [3]. Based on their measured transfer cross section much higher than the breakup cross section at the near barrier energy for the 6,7 Li + 28 Si system, Pakou et al [4][5][6][7][8] argue that transfer channels can also be important at low energies for some weakly bound systems, and therefore those channels may be the main reason for the nondecreasing of the imaginary potential at near barrier energies. The BTA has been investigated in a large number of nuclear systems involving weakly bound projectiles with a variety of medium and large mass targets, for instance 9 Be with 27 Al [9], with 64 Zn [10][11][12][13], with 144 Sm [14,15] and with 208 Pb, 209 Bi [16,17]; 6 Li and 7 Li with targets 208 Pb [3,18], 27 Al [19][20][21], 144 Sm [22], 58,64 Ni [23,24], 59 Co [25], 90 Zr [26], 138 Ba [11,27,28], 28 Si [6].…”

mentioning

confidence: 99%

“…The total reaction cross sections σ T are those from Refs. [5,38]. For 7 Li + 28 Si, elastic scattering, fusion and total reaction cross section data are those of Refs.…”

mentioning

confidence: 99%

“…For 7 Li + 28 Si, elastic scattering, fusion and total reaction cross section data are those of Refs. [6,39,40] and [5,7], respectively. In the simultaneous fitting calculations, we used fixed diffuseness and reduced radii for the fusion and direct reaction potentials for all energies: a F = 0.6 fm, r F = 1.4 fm, a DR = 0.6 fm, and r DR = 1.6 fm for 6 Li + 28 Si and a F = 0.6 fm, r F = 1.4 fm, a DR = 0.7 fm, and r DR = 1.6 fm for 7 Li + 28 Si.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Optical model calculations on the threshold anomaly for theLi6+<

2010

View full text Add to dashboard Cite

A simultaneous analysis of elastic scattering, fusion, and total reaction cross sections for the weakly bound systems 6,7 Li + 28 Si at energies close to the Coulomb barrier is performed by optical model calculations. The nuclear polarization potential U is split into volume part U F , which accounts for fusion reactions and a surface part U DR , responsible for direct reactions. The parameters of the Woods-Saxon potentials are determined by a χ 2 analysis of the data. The presence of the threshold anomaly or the breakup threshold anomaly is investigated from the energy dependence of both the fusion and direct reaction parts of the polarization potential.For some time it has been known that reactions with heavy systems present the so-called threshold anomaly (TA), i.e., the real and imaginary parts of the optical potential obtained from elastic scattering fits around the Coulomb barrier, and show a distinctive energy dependent behavior. The imaginary potential drops sharply as the energy decreases toward the barrier energy, while the real potential strength shows a strong localized peak around the barrier. At higher energies both potentials are almost energy independent [1]. This energy behavior of the optical potential is understood in terms of the strong coupling between the elastic scattering channel to other reaction channels that produce an attractive polarization potential. The absolute value of this attractive real polarization potential increases the strength of the already attractive nuclear potential which, in turn, lowers the fusion barrier and consequently produces an enhancement of the fusion cross sections at energies below the Coulomb barrier. This energy dependence of the real potential is expressed frequently bywhere V 0 is the real nuclear potential at high energies and V (E) the polarization potential. The decrease of the imaginary potential W (E) of the optical potential as the collision energy approaches the barrier is due to the closing of reaction channels. It is also well known that the energy dependence between the real and imaginary polarization potentials are connected by the dispersion relation expressed by the principal integral value [2],It is then clear that any strong change in W (E) must be accompanied by a localized strong variation in V (E). In the case where weakly bound projectiles are involved, many studies reveal that the situation is quite different. Due to the weak binding energy of the nucleus, strong couplings between breakup and elastic channels at energies below the Coulomb barrier may arise. In such a situation, the imaginary part W (E) of the optical potential cannot sharply decrease, as it does for tightly bound nuclei, since it must account for the appreciable breakup cross-section yields observed at energies below the barrier. Accordingly, the real part of the polarization potential V (E) does not contribute to an increase in the strength of the nuclear potential, but instead has a repulsive characteristic. This new phenomenon has been termed the breakup threshold...

show abstract