Transfer reactions provide information about the single-particle nature of nuclear levels. In particular, the differential cross sections from these measurements are sensitive to the angular momentum of the transferred particle and the spectroscopic factor of the populated level. However, the process of extracting these properties is subject to uncertainties, both from experimental and theoretical sources. By integrating the distorted wave Born approximation into a Bayesian model, we propagate these uncertainties through to the spectroscopic factors and orbital angular momentum values. We use previously reported data of the proton pickup reaction $^{70}$Zn$(d, ^3\!\text{He}) ^{69}$Cu as an example. By accounting for uncertainties in the experimental data, optical model parameters, and reaction mechanism, we find that the extracted spectroscopic factors for low lying states of $^{69}$Cu are subject to large, asymmetric uncertainties ranging from $35 \%$ to $108 \%$. Additionally, Bayesian model comparison is employed to assign probabilities to each of the allowed angular momentum transfers. This method confirms the assignments for many states, but suggests that the data for a state lying at $3.70$ MeV is better characterized by an $\ell = 3$ transfer, rather than the previously reported $\ell = 2$.
The production of new proton-rich nuclei in the vicinity of 100Sn is investigated via multinucleon transfer reactions within the framework of microscopic time-dependent Hartree-Fock (TDHF) and statistical model GEMINI++. The TDHF+GEMINI method has demonstrated the reliable description in the multinucleon transfer dynamics and the agreement between theoretical results and experimental data is quite satisfactory in the observed transfer reactions. We reveal the production cross sections of proton-rich nuclei in 100Sn region via multinucleon transfer reactions to be several orders of magnitude hi…
The Bayesian neural network (BNN) method is used to construct a predictive model for fragment prediction of proton induced spallation reactions with the guidance of a simplified EPAX formula. Compared to the experimental data, it is found that the BNN + sEPAX model can reasonably extrapolate with less information compared with BNN method. The BNN + sEPAX method provides a new approach to predict the energy-dependent residual cross sections produced in proton-induced spallation reactions from tens of MeV/u up to several GeV/u.
Transfer reactions are essential to determine spectroscopic factors and astrophysical reaction rates. However, their theoretical evaluation is typically effected using standard reaction theory, from which structure degrees of freedom are absent. While reaction cross sections have been implemented in the frame of the no-core shell model with continuum, this model can be applied in practice only to the lightest nuclei. The use of the core + valence nucleon picture is then necessary to include inter-nucleon correlations in reaction cross sections involving medium nuclei. For this, we will use the…
Fragments productions in spallation reactions are key infrastructure data for various applications. Based on the empirical parameterizations {\sc spacs}, a Bayesian-neural-network (BNN) approach is established to predict the fragment cross sections in the proton induced spallation reactions. A systematic investigation have been performed for the measured proton induced spallation reactions of systems ranging from the intermediate to the heavy nuclei and the incident energy ranging from 168 MeV/u to 1500 MeV/u. By learning the residuals between the experimental measurements and the {\sc spacs} …
Within the dinuclear system model, unknown neutron-deficient isotopes Np, Pu, Am, Cm, Bk, Cf, Es, Fm are investigated in $^{40}$Ca, $^{36,40}$Ar, $^{32}$S, $^{28}$Si,$^{24}$Mg induced fusion-evaporation reactions and multinucleon transfer reactions with radioactive beams $^{59}$Cu,$^{69}$As,$^{90}$Nb,$^{91}$Tc, $^{94}$Rh, $^{105,110}$Sn, $^{118}$Xe induced with $^{238}$U near Coulomb barrier energies. The production cross sections of compound nuclei in the fusion-evaporation reactions and fragments yields in the multinucleon transfer reactions are calculated within the model. A statistical app…
Multi-neutron transfer coupling in sub-barrier 32S+90,96Zr fusion reactions
以32S+90Zr和32S+96Zr为基准反应,研究了库仑势垒以下聚变过程中中子转移的作用.一个完整的耦合通道计算的聚变激发函数已进行了两个系统,通过使用多中子转移耦合的中子更丰富的反应。通过NTFus程序计算,包括Zagrebaev半经典模型下的中子转移通道的耦合,在亚势垒能量下很好地再现了32 S +96 Zr的熔合截面的增强。我们发现40Ca+90Zr和40Ca+96Zr熔合激发函数的效应相似。
The $^3{\rm H}(d,n)^4{\rm He}$ reaction is of significant interest in nuclear astrophysics and nuclear applications. It is an important, early step in big-bang nucleosynthesis and a key process in nuclear fusion reactors. We use one- and two-level $R$-matrix approximations to analyze data on the cross section for this reaction at center-of-mass energies below 215 keV. We critically examine the data sets using a Bayesian statistical model that allows for both common-mode and additional point-to-point uncertainties. We use Markov Chain Monte Carlo sampling to evaluate this $R$-matrix-plus-statis…
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…
Description of multinucleon transfer mechanism for ${}^{48} \mathrm{Ca}+{ }^{244} \mathrm{Pu}$ and ${ }^{86} \mathrm{Kr}+{}^{198} \mathrm{Pt}$ reactions in quantal transport approach
Coupled-channels analyses for $^{9,11}$Li + $^{208}$Pb fusion reactions with multi-neutron transfer couplings
讨论了双中子转移过程在$^{9,11}$ Li + $^{208}$ Pb系统聚变反应中的作用。我们首先通过考虑与$^{7}$ Li + $^{210}$ Pb通道的耦合来分析$^{9}$ Li + $^{208}$ Pb反应。为此,我们假设两个中子直接转移到$^{210}$ Pb中的单个有效通道,并求解具有两个通道的耦合通道方程。通过调整耦合强度和有效$Q$值,我们成功地再现了该系统的实验熔合截面。然后,我们以类似的方式分析$^{11}$ Li + $^{208}$ Pb反应,即,通过考虑$^{11}$ Li + $^{208}$ Pb、$^{9}$ Li + $^{210}$ Pb和$^{7}$ Li + $^{212}$ Pb分区的三个有效通道。为了考虑$^{11}$ Li核的晕结构,我们用双重折叠方法构造了$^{11}$ Li和$^{208}$ Pb之间的势,而对于其它通道我们采用了具有整体Akyüz-Winther参数的Wood-Saxon型势.计算结果表明,在库仑势垒附近的$^{11}$ Li + $^{208}$ Pb聚变反应中,多次双中子转移过程起着决定性的作用.