作者机构：
[谭清懿; 杨开建; 乔冠瑾] Department of Electrical Engineering, University of South China, Hengyang, 421001, China;[杜丹] Department of Mathematics and Physics, University of South China, Hengyang, 421001, China;[潘光祖; 周华; 龚学余] Department of Nuclear Science and Technology, University of South China, Hengyang, 421001, China
通讯机构：
[Du, D.] D;Department of Mathematics and Physics, China
作者机构：
[李金阳; 刘依诺; Zeng, Wenjie; 胡杨; 于涛] School of Nuclear Science and Technology, University of South China, Hengyang;421001, China;[李金阳; 刘依诺; Zeng, Wenjie; 胡杨; 于涛] 421001, China
通讯机构：
School of Nuclear Science and Technology, University of South China, Hengyang, China
作者机构：
[余清远; 赵鹏程] School of Nuclear Science and Technology, University of South China, Hengyang;421001, China;[马誉高] Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu;610213, China;[余清远] 421001, China
摘要：
本文提出基于NB-IoT(Narrow Band Internet of Things,窄带物联网)技术的核辐射剂量仪研制方案,该仪器采用STM32F103系列单片机作为主控芯片,辐射剂量探测器选用G-M计数管,集成温湿度采集模块,通过BC20物联网模块将采集数据发送到OneNet云平台,云平台能够实时监控仪器所在位置的辐射剂量值以及温湿度值,同时显示仪器的北斗定位信息。该辐射剂量仪能够实现远程实时监测、定位,具备轻量化,低功耗,低成本,覆盖范围广等特点。
通讯机构：
[Guoqiang Zhang; Wenjun Ma] S;State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, CAPT, School of Physics, Peking University , Beijing 100871, China<&wdkj&>Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201800, China
摘要：
In this work, the high-energy-density plasmas (HEDP) evolved from joule-class-femtosecond-laser-irradiated nanowire-array (NWA) targets were numerically and experimentally studied. The results of particle-in-cell simulations indicate that ions accelerated in the sheath field around the surfaces of the nanowires are eventually confined in a plasma, contributing most to the high energy densities. The protons emitted from the front surfaces of the NWA targets provide rich information about the interactions that occur. We give the electron and ion energy densities for broad target parameter ranges. The ion energy densities from NWA targets were found to be an order of magnitude higher than those from planar targets, and the volume of the HEDP was several-fold greater. At optimal target parameters, 8% of the laser energy can be converted to confined protons, and this results in ion energy densities at the GJ/cm3 level. In the experiments, the measured energy of the emitted protons reached 4 MeV, and the changes in energy with the NWA’s parameters were found to fit the simulation results well. Experimental measurements of neutrons from 2H(d,n)3He fusion with a yield of (24 ± 18) × 106/J from deuterated polyethylene NWA targets also confirmed these results.
摘要：
ALETHEIA (a liquid hElium time projection cHambEr In dark matter) project is an originally creative dark matter experiment aiming to search for low-mass (100 MeV/c(2)-10 GeV/c(2)) WIMPs. While there have existed more than ten experiments doing research on low-mass WIMPs, the ALETHEIA is supposed to grow up to be a leading project worldwide due to many unique advantages, including but are not limited to extremely low intrinsic backgrounds, easy purification, and strong potential capability of signal/background discrimination. Owing to the project's original creativity, there has existed no direct experience of building such a detector yet; consequently, we have to launch a set of R&D programs from scratch, including the TPB coating process conveyed in this paper. An incident particle that hits a liquid helium detector would generate 80-nm-long scintillation. There are currently no commercially available photon detectors capable of efficiently detecting the scintillation light and a wavelength converter must be used to convert the 80-nm-long scintillator into visible light. Silicon photomultipliers (SiPMs) can then be implemented to detect the 450-nm-wavelength light. The TPB (Tetraphenyl Butadiene, 1, 1,4, 4-tetraphenyl-1, 3-butadiene) is widely used for realizing the conversion. Although in thedark matter experiment using argon pulse-shape discrimination (DEAP), 2.3-mu m-thick TPB is successfully coated on the inner wall of the sphere with a radius of 85 cm, we cannot mimic the whole process in our experiment directly out of the two following reasons: (a) our detector shape is cylindrical, not spherical, and (b) the diameter of the current detector prototype is only 10 cm, while the one of the DEAP detectors is as large as 1.7-meter. Consequently, we must design and build an appropriate coating apparatus suitable for our detector. Owing to the existence of necessary auxiliary parts (such as cables for heating and temperature sensors), on which some vapored TPB molecules would be deposited when the coating is in progress. As a result, a blind spot on the inner wall always exists that cannot be fully coated; the blind spot area will affect the visible light yield of 80-nm-long scintillation. To solve the problem, we split the coating process into two steps: coating the curved surface and one base together in the first step and coating another base in the second step. In this way, the cylindrical detector's whole inner wall (the curved surface and the two bases) will be coated. Another key technology is to design an appropriate source sphere containing TPB powder. There are 20 holes evenly distributed on the surface of the sphere. After the TPB powder is heated andevaporated into the gas, the TPB molecules should move slowly enough to ensure that they scatter from each other long enough within the source before randomly finding a hole to escape. As a result, the TPB molecules come out of the source in an isotropic way then adhere to the inner surfaces of a cylindrical detector (diameter and height are both 10 cm) with nearly the same thickness. The TPB coating thickness on the inner wall is in a range between 1.50 and 3.02 mu m, which corresponds to the thinnest and thickest TPB plate, respectively. The variation mainly comes from the different distances from the coating place to the source, which lies at the center of the PTFE cylinder. The thickness difference will not bother us because the conversion efficiency for 80-nm-long scintillation is almost the same as that for the TPB thickness in a range from 0.7 to 3.7 mu m. In addition to introducing the ALETHEIA project briefly at the beginning, we mainly address several aspects of TPB coating: coating principle, source design, coating process, coating thickness monitoring, and the comparison of thickness among coating plates from three independent methods. The whole process addressed in this paper is expected to provide a valuable reference for other experiments with similar requirements.
作者机构：
[Li, Xiao-Hua; Pan, Xiao; Zou, You-Tian] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Li, Xiao-Hua; Wu, Xi-Jun] Univ South China, Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Peoples R China.;[Li, Xiao-Hua] Hunan Normal Univ, Key Lab Low Dimens Quantum Struct & Quantum Contr, Changsha 410081, Peoples R China.;[Wu, Xi-Jun] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[He, Biao] Cent South Univ, Coll Phys & Elect, Changsha 410083, Peoples R China.
通讯机构：
[Xiao-Hua Li] S;School of Nuclear Science and Technology, University of South China, Hengyang 421001, China<&wdkj&>Cooperative Innovation Center for Nuclear Fuel Cycle Technology & Equipment, University of South China, Hengyang 421001, China<&wdkj&>Key Laboratory of Low Dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410081, China
关键词：
favored one proton radioactivity;one-parameter model;half-lives
摘要：
According to gauge/gravity duality, we use an Einstein-Maxwell-dilaton (EMD) model to study the running coupling constant at finite chemical potential and magnetic field. First, we calculate the effect of temperature on the running coupling constant and find the results are qualitatively consistent with lattice guage theory. Subsequently, we calculate the effect of chemical potential and magnetic field on running coupling. It is found that the chemical potential and magnetic field both suppress the running coupling constant. However, the effect of the magnetic field is slightly larger than that of chemical potential for a fixed temperature. Compared with the confinement phase, the magnetic field has a large influence on the running coupling in the deconfinement phase.
作者机构：
[Junjie Li; Xin Ling; Yong Deng; Fengbo Gu; Xiaohui Qi; Guopu Qu] School of Nuclear Science and Technology, University of South China, Hengyang, China;Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing, China;State Key Laboratory of Particle Detection and Electronics, Institute of High Energy Physics, CAS, Beijing, China;University of Chinese Academy of Sciences, Beijing, China;[Xiaoxue Fan] Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, School of Nuclear Science and Engineering, North China Electric Power University, Beijing, China
通讯机构：
[Xilei Sun] I;[Guopu Qu] S;School of Nuclear Science and Technology, University of South China, Hengyang, China
摘要：
Radon is a noble gas, which endangers our health. The liquid scintillator is one of the detector materials used to measure radon in the environment. But there are challenges in measuring radon using a liquid scintillator, such as independent manual operation and long measurement periods. We propose a liquid scintillator detector for the rapid measurement of radon, which is composed of a breathable liquid scintillator probe and photomultiplier tube. Cascade decay recognition and pulse shape discrimination (PSD) were used to select radon events.
$$^{241}$$
Am4(
$$\alpha $$
) and
$$^{90}$$
Sr(
$$\beta $$
) source calibration was used to optimize the PSD figure of merit of the liquid scintillator, and a
$$^{232}$$
Th (
$$^{220}$$
Rn) diffusion source was used to verify the function of this novel detector for measuring radon. The detector had an integrated design for sampling and measurement, which simplified the measurement steps. Thus, this novel liquid scintillator detector demonstrated promise for use in radon-detection systems.
通讯机构：
[Xiao-Dong Wang] S;School of Nuclear Science and Technology, University of South China, Hengyang, China
关键词：
Monte Carlo simulation;Muon tomography;Image reconstruction
摘要：
Muon tomography is a novel method for the non-destructive imaging of materials based on muon rays, which are highly penetrating in natural background radiation. Currently, the most commonly used imaging methods include muon radiography and muon tomography. A previously studied method known as coinciding muon trajectory density tomography, which utilizes muonic secondary particles, is proposed to image low and medium atomic number (Z) materials. However, scattering tomography is mostly used to image high-Z materials, and coinciding muon trajectory density tomography exhibits a hollow phenomenon in the imaging results owing to the self-absorption effect. To address the shortcomings of the individual imaging methods, hybrid model tomography combining scattering tomography and coinciding muon trajectory density tomography is proposed and verified. In addition, the peak signal-to-noise ratio was introduced to quantitatively analyze the image quality. Different imaging models were simulated using the Geant4 toolkit to confirm the advantages of this innovative method. The simulation results showed that hybrid model tomography can image centimeter-scale materials with low, medium, and high Z simultaneously. For high-Z materials with similar atomic numbers, this method can clearly distinguish those with apparent differences in density. According to the peak signal-to-noise ratio of the analysis, the reconstructed image quality of the new method was significantly higher than that of the individual imaging methods. This study provides a reliable approach to the compatibility of scattering tomography and coinciding muon trajectory density tomography.
作者机构：
[杨光; 钟翊君; 龚学余; 黄千红] Department of Nuclear Science and Technology, University of South China, Hengyang, 421001, China;[郑平卫] Department of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, China;[王占辉] Institute of Fusion Sciences, Southwestern Institute of Physics, Chengdu, 610000, China
通讯机构：
[Zhong, Y.; Gong, X.] D;Department of Nuclear Science and Technology, China
关键词：
杂质输运;电子回旋波
摘要：
本文基于OMFIT(One Modeling Framework for Integrated Tasks)平台,结合中国环流器二号M(HL-2M)托卡马克装置参数,自洽耦合等离子体平衡、外部辅助加热和电流驱动、输运等物理过程,考虑杂质浓度变化引起的等离子体密度、温度等输运量变化,以及引起的等离子体磁面中心Shafranov位移变化,从理论上进行杂质浓度变化对电子回旋波(Electron Cyclotron Wave,ECW)沉积位置和驱动电流效率的影响研究.研究结果表明,考虑杂质对等离子体的影响时,随着杂质浓度的增加,ECW沉积径向位置先向等离子体芯部移动然后向边缘移动,电流驱动效率先增加后减小.不考虑杂质对等离子体影响时,ECW沉积位置基本不变,电流驱动效率降低.
