The vast knowledge of strong influence of quadrupole deformation $β_2$ of colliding nuclei on heavy-ion subbarrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as $β_4$ and $β_6$ deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of $β_4$ of the projectile nucleus in fusion of the $^{28}$Si + $^{92}$Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and the value of the $β_4$ parameter of the projectile, $^{28}$Si, and confirmed that the $^{28}$Si nucleus has a large positive $β_4$. This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult due to experimental constraints.
Quasi-elastic (QEL) scattering measurements have been performed using $^{28}$Si projectile off a $^{90}$Zr target at energies around the Coulomb barrier. A Bayesian analysis within the framework of coupled channels (CC) calculations is performed in a large parameter space of quadrupole and hexadecapole deformations ($β_{2}$ and $β_{4}$) of $^{28}$Si. Our results clearly show that $^{28}$Si is an oblate shaped nucleus with $β_{2}$=-$0.38 \pm 0.01$ which is in excellent agreement with electromagnetic probes. A precise value of hexadecapole deformation for $^{28}$Si, $β_{4}$=+$0.03 \pm 0.01$, alo…
Quasi-elastic scattering measurements have been performed using $^{16}$O and $^{24}$Mg projectiles off $^{90}$Zr at energies around the Coulomb barrier. Experimental data have been analyzed in the framework of coupled channels (CC) calculations using the code CCFULL. The quasi-elastic scattering excitation function and derived barrier distribution for $^{16}$O + $^{90}$Zr reaction are well reproduced by the CC calculations using the vibrational coupling strengths for $^{90}$Zr reported in the literature. Using these vibrational coupling strengths, a Bayesian analysis is carried out for $^{24}$…
Breakup of $^{9}$Be on $^{209}$Bi above and near the Coulomb barrier as a molecular single-particle effect: its influence on complete fusion and scattering
用绝热双中心壳模型方法研究了轰击能量在库仑势垒之上和附近时，$^{9}$ Be弹丸在$^{209}$ Bi靶上的破碎。研究了$^{9}$ Be $% \to $ n $+2α$破碎通道对完全熔合、弹性和非弹性截面的影响。结果表明，在碰撞核到达库仑势垒之前不久，抛射体$^{9}$ Be的分裂可能是由于分子单粒子效应。
The total fusion cross sections for the fusion of weakly bound $^{9}$Be on $^{27}$Al and $^{64}$Zn targets at near and above the barrier have been calculated using one dimensional barrier penetration model, taking scattering potential as the sum of Coulomb and proximity potential and the calculated values are compared with experimental data. For the purpose of comparison of the fusion of weakly bound projectiles and strongly bound projectiles, the total fusion cross sections for the reaction of tightly bound nucleus $^{16}$O on $^{64}$Zn have also been computed using a similar procedure. The c…
We have calculated the multinucleon transfer reactions of $^{208}$Os, $^{208}$Pt, $^{208}$Hg, $^{208}$Pb,$^{208}$Po, $^{208}$Rn, $^{208}$Ra,$^{132,136}$Xe bombarding on $^{232}$Th and $^{248}$Cm at Coulomb barrier energies within the dinuclear system model, systematically. The results are in good agreement with the available experimental data. Coulomb effect and shell effect on production of actinides in these reactions have been investigated thoroughly. Potential energy surface and total kinetic energy mass distributions in the reactions $^{208}$Hg, $^{208}$Pb and$^{208}$Po colliding on $^{24…
The virtual photon theory (VPT), which is based on first-order Coulomb dissociation restricted to the electric dipole ($E1$), has been successfully used to explain the breakup data for several cases. Our aim is to study the role of various higher-order processes that are ignored in the VPT, such as the nuclear breakup, interference between nuclear and Coulomb amplitudes, and multistep breakup processes mainly due to strong continuum-continuum couplings in the breakup of two-body projectiles on a heavy target at both intermediate and higher incident energies. For the purpose of numerical calcul…
The production of $α$-particles in reactions using both the strongly and weakly bound projectiles at energies around the Coulomb barrier show several interesting features. To understand these, the role of various reaction mechanisms responsible for $α$-production, such as non-capture breakup, capture of only one of the fragments subsequent to projectile breakup and their contribution to reaction cross sections have been investigated. A systematic study of the $α$-particle production based on available data for various projectile target systems have been performed and a classification based on …
In this work we measured elastic and inelastic angular distributions of the weakly bound 9Be projectile on the 197Au target at several bombarding energies from 84% up to 140% of the Coulomb barrier. The elastic angular distributions were analyzed using a phenomenological Woods-Saxon potential and a double folding Sao Paulo potential and the energy dependence was extracted. Angular distributions from two inelastic peaks were compared with coupled channel calculations using reduced transition probabilities available in the literature. The energy dependence of the two interaction potential models…
Probable projectile-target combinations for the synthesis of superheavy element $^{302}$120 have been studied taking Coulomb and proximity potential as the interaction barrier. The probabilities of compound nucleus formation, PCN for the projectile-target combinations found in the cold reaction valley of $^{302}$120 are estimated. At energies near and above the Coulomb barrier, we have calculated the capture, fusion and evaporation residue cross sections for the reactions of all the probable projectile-target combinations so as to predict the most promising projectile-target combinations for t…
Coupled-Channel Effects in Collisions between Heavy Ions near the Coulomb Barrier
近年来，随着重离子稳定束和放射性核束的出现，重离子核反应的研究又引起了人们的兴趣。我首先介绍的作用，非弹性和转移通道耦合在聚变反应引起的稳定重离子。本文讨论了用标准耦合道计算方法分析实验熔合截面的问题。以$^{32}$ S + $^{90,96}$ Zr为基准反应，研究了多中子转移在库仑势垒以下聚变过程中的作用.利用NTFus程序计算了$^{32}$ S + $^{96}$ Zr在亚势垒能区的熔合截面的增强，其中包括中子转移通道的耦合，采用Zagrebaev半经典模型。对$^{40}$ Ca + $^{90}$ Zr和$^{40}$ Ca + $^{96}$ Zr的熔合激发函数也发现了类似的效应，同时还发现了在弹性散射和熔合过程中由弱束缚稳定射弹引起的破碎耦合也是至关重要的.在这个讲座中，全耦合通道计算的聚变激发函数进行分裂耦合的中子更丰富的反应和更弱的约束射弹。我清楚地表明，连续离散耦合通道计算是能够再现的$^{6}$锂+$^{59}$公司的分裂耦合的融合增强。
Sensitivity of 8B breakup cross section to projectile structure in CDCC calculations
鉴于$^7$ Be $(p,γ)^8$ B的天体物理学意义，已经有几个实验应用库仑解离方法提取捕获率。密歇根州立大学的测量主要由$E1$贡献，但有一个小的$E2$组件。另一方面，在巴黎圣母院的较低能量测量具有更强的$E2$贡献。预期这两个测量值将束缚$E2$，从而允许准确提取与捕获过程相关的$E1$。这份简要报告的目的是表明，裂解反应中的$E2$因子不会转化为相应捕获反应中$E2$贡献的比例。我们表明，$^8$ B单粒子参数的变化，这是直接相关的$E2$组件在捕获反应，不影响相应的分裂反应，使用本反应理论。
The Coulomb-nuclear interference is studied as a function of the projectile ground-state binding energy in the 8Li + 12C and 8Li + 208Pb breakup reactions, by considering an arbitrary range for the 8Li ground-state binding energies εb, varying from the experimental one 2.03 MeV down to 0.01 MeV. Regardless the target mass, we first show that the Coulomb breakup cross section is stronger dependent on εb than the nuclear breakup cross section, due to the long-range nature of the Coulomb forces and to the electromagnetic transition matrix elements. For example, in case of 8Li + 208Pb reaction at …
Role of break-up processes in fusion enhancement of drip-line nuclei at energies below the Coulomb barrier
本文对$^{11}$ Be + $^{208}$ Pb反应进行了真实的耦合道计算，讨论了入射核破碎对亚势垒熔合的影响。我们离散的粒子连续态，这是与破碎过程中，并构造耦合形状因子，这些国家的微观基础上的能量。引入边界条件求解耦合通道方程，从而定义了库仑势垒内完全聚变的通量。结果表明，完全熔合截面显着增强，由于连续态的耦合相比，没有耦合的情况下，在能量低于库仑势垒，而他们被阻碍在势垒以上的能量。
We investigate the low-energy $^9$Be elastic scattering on two different targets (heavy, light) within a four-body framework using the Continuum-Discretized Coupled-Channels (CDCC) method. The $^9$Be projectile is described in a $α+ α+ n$ three-body model using the analytical transformed harmonic oscillator (THO) basis in hyperspherical coordinates. We show that continuum couplings are important to describe the elastic cross section, especially at low energies and on heavy targets. The dipolar contribution to the elastic cross section at energies around the Coulomb barrier is important but sma…
