## 2020年  第37卷  第2期

2020, 37(2): 1-2.

2020, 37(2): 119-135. doi: 10.11804/NuclPhysRev.37.2019060

2020, 37(2): 136-150. doi: 10.11804/NuclPhysRev.37.2019068

The nuclear symmetry energy, which describes the energy difference of per proton and neutron in nuclear matter, has been extensively studied within the last two decades. Around saturation density, both the value and the slope of the nuclear symmetry energy have been roughly constrained, its high-density behavior is now still in argument. Probing high-density symmetry energy at terrestrial laboratories is being carried out at facilities that offer radioactive beams worldwide. While relevant experiments are being conducted, we theoretically developed more advanced isospin-dependent transport model including new physics such as nucleon-nucleon short-range correlations and in-medium isospin-dependent baryon-baryon scattering cross section. New sensitive probes of the high-density symmetry energy are provided, such as squeezed-out neutron to proton ratio, photon and light cluster as well as the production of mesons with strangeness or hidden strangeness. The blind spots of probing the high-density symmetry energy by sensitive observable are demonstrated. Model dependences of frequently used sensitive probes of the symmetry energy have been studied thoroughly based on different transport models. A qualitative observable of neutron to proton ratio at high kinetic energy is proposed to probe the high-density symmetry energy qualitatively. The probed density regions of the symmetry energy by some observables are first studied and usually lower probed density regions comparing with maximum compression density are obtained. Nucleon-nucleon short-range correlations usually reduce values of sensitive observables of the symmetry energy. Probing the curvature of the symmetry energy by involving the slope information of the symmetry energy at saturation point in the transport model is proposed. Besides constraining the high-density symmetry energy by using heavy-ion collisions, a lot of neutron-star related observations from heaven may also be used to constrain the high-density symmetry energy.
2020, 37(2): 151-159. doi: 10.11804/NuclPhysRev.37.2020005

2020, 37(2): 160-165. doi: 10.11804/NuclPhysRev.37.2020022

Multinucleon transfer reaction 136Xe+208Pb at \begin{document}$E_{\rm{c.m.}}$\end{document}=617 MeV is simulated by improved quantum molecular dynamics (ImQMD) model with and without considering the effect of \begin{document}$Q$\end{document}-value. The calculation results of ImQMD including the effect of \begin{document}$Q$\end{document}-value (ImQMD+\begin{document}$Q$\end{document}) generally better reproduce the experimental mass distribution and distribution of total kinetic energy lost (TKEL). \begin{document}$Q$\end{document}-value effect is found to drive the transfer of less than ten nucleons and suppress more nucleons transfer. It also decreases the average lifetime of composite systems in the events at lower impact parameters. In the production of more neutron-rich isotopes with neutron number \begin{document}$N$\end{document}=126, \begin{document}$Q$\end{document}-value effect enhances the cross sections for these isotopes in the comparison between the results of ImQMD and ImQMD+\begin{document}$Q$\end{document}.
2020, 37(2): 166-171. doi: 10.11804/NuclPhysRev.37.2020008

We study the large transverse momentum dilepton produced by the photon-nucleon interactions in the peripheral Au-Au collisions at RHIC and Pb-Pb collisions at LHC. We calculate the dilepton production yield by using the perturbative QCD factorization approach and the Weizsäcker-Williams approximation. The numerical results indicate that the photon-nucleon collision processes is negligible by comparing with the conventional large transverse momentum dilepton production at RHIC energies. However, in the large transverse momentum region, the photon-nucleon collision could be an important large transverse momentum dilepton source in the peripheral heavy ion collisions at LHC.
2020, 37(2): 172-179. doi: 10.11804/NuclPhysRev.37.2020007

2020, 37(2): 180-185. doi: 10.11804/NuclPhysRev.37.2019058

2020, 37(2): 186-190. doi: 10.11804/NuclPhysRev.37.2020013

2020, 37(2): 191-198. doi: 10.11804/NuclPhysRev.37.2020024

LHAASO(Large High Altitude Air Shower Observatory)WCDA(Water Cerenkov Detector Array)要求其读出电子学实现大动态范围下精确的时间和电荷测量，为此设计了一款前端读出芯片PASC(Pre-Amplifier and Shaping Circuit) ASIC(Application Specific Integrated Circuit)，即将用于LHAASO WCDA第三水池的读出。为了满足对此芯片大批量测试需求，设计了此ASIC测试系统，实现了对芯片时间和电荷性能的自动化测试。在介绍此芯片基本工作原理的基础上，讨论了测试系统的设计方案和基本结构，包括硬件电路设计和自动化测试软件设计。该测试系统已应用于LHAASO工程项目的芯片筛选并且已完成了100片芯片的测试工作，能够通过中央控制软件，与多台仪器通讯，进行仪器控制，完成自动化测试和数据记录。这一自动化测试方法，更适用于大动态范围下、高精度读出芯片的性能测试和评估，大大简化测试流程，尤其能够大幅提升批量测试中大量重复性测试步骤的工作效率。文中展示了基于此测试系统已完成的100片芯片的测试结果，结果表明，芯片各项性能参数满足LHAASO第三水池工程应用需求。

2020, 37(2): 199-208. doi: 10.11804/NuclPhysRev.37.2020020

2020, 37(2): 209-216. doi: 10.11804/NuclPhysRev.37.2020015

In order to provide a basic understanding on the effect of H on He behaviors in the structural materials for the future nuclear systems, the effect of H on He thermal desorption and retention behaviors in SIMP steels was studied using thermal desorption spectroscopy(TDS), scanning electron microscope(SEM), and transmission electron microscopy(TEM) by comparing the results of the alone irradiation of 130 keV He+ and the sequential irradiation of 130 keV He+ and 160 keV H2+. The TDS results show that a major peak of He release occurred in the temperature of 1 198~1 222 K via the mechanism of bubble migration. The peak temperature of He release was lower and the release amount was larger under the sequential irradiation of He+ and H2+ than that under the He+-alone irradiation. This indicates that He desorption was enhanced by the additional H irradiation. In addition, the enhancement effect of H on He thermal desorption depends on the dose of H irradiation. When the peak concentration of H increased from 5% to 50% (atom fraction), this enhancement effect was weakened. Combined with TEM and SEM results, it was found that the presence of H promoted the surface blistering during TDS heating, thus accelerating the release of He by the mechanism of bubble migration.

2020, 37(2): 217-224. doi: 10.11804/NuclPhysRev.37.2019050

2020, 37(2): 225-232. doi: 10.11804/NuclPhysRev.37.2019065

2020, 37(2): 233-239. doi: 10.11804/NuclPhysRev.37.2020003

2020, 37(2): 240-248. doi: 10.11804/NuclPhysRev.37.2020010

This paper presented a study of flowability of the inclined dense granular-flow target for a neutron irradiation facility, which is capable of providing high-energy neutrons suitable to advance fusion reactor material research. The results from simulations and theoretical analysis described the constancy and stability of the flow, which was rarely mentioned before. It was found that 25° was acceptable for a steady and stable accelerating flow and all the results supported the availability of this granular flow for a potential choice of the heat medium.