作者机构：
[朱志超; 罗文; 宋英明; 王晓冬; 李卓成; 王兴柳] School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China;[范功涛] Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China
通讯机构：
School of Nuclear Science and Technology, University of South China, Hengyang, China
作者：
Cao, Jinjia;Gong, Xueyu*;Xiang, Dong;Huang, Qianhong;Yu, Jun
期刊：
PHYSICS OF PLASMAS,2016年23(8):082301 ISSN：1070-664X
通讯作者：
Gong, Xueyu
作者机构：
[Xiang, Dong; Huang, Qianhong; Gong, Xueyu; Cao, Jinjia] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Yu, Jun] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
通讯机构：
[Gong, Xueyu] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
plasma interactions;plasma transport processes
摘要：
The structure of the drift-island surface of passing fast ions (PFIs) is investigated in the presence of the resonant interaction with a magnetic island. Two overlapping regions of the drift-island surface and the magnetic island surface are found, one corresponding to local overlapping region and the other to non-local one. Here, the word “nonlocal” denotes that the resonances in the core plasma can have effects on the PFIs near the plasma boundary, while the “local” represents that the PFIs just near the resonant location are influenced. The nonlocal overlapping constructs a transport path along which the PFIs can become losses. There are three kinds of drift-island surfaces to join in forming the transport paths. A pitch angle region, which is called pitch angle gap, is found near the plasma boundary, where the drift-island surface cannot be formed and few PFIs are lost. The pitch-angle selective features of PFI losses are obtained by analyzing the three kinds of drift-island surfaces. The coupling between the crowd drift island surfaces and the collision can induce the prompt losses of PFIs and rapidly slowing down of PFI energy. The time of the prompt losses and the slowing down rate are calculated. Qualitatively, the theoretical results are in well agreement with the experimental observations in ASDEX Upgrade [M. García-Muñoz et al., Nucl. Fusion 47, L10 (2007)].
作者机构：
[邱睿; 武祯; 李君利; 陈宜正] Key Laboratory of Particle and Radiation Imaging of Ministry of Education, Department of Engineering Physics, Tsinghua University, Beijing, 100084, China;[康玺] School of Nuclear Science &, Technology, University of South China, Hengyang, 421001, China
通讯机构：
Key Laboratory of Particle and Radiation Imaging of Ministry of Education, Department of Engineering Physics, Tsinghua University, Beijing, China
关键词：
剂量当量;迷宫;中子;感生γ光子;Monte Carlo模拟
摘要：
医用高能加速器在广泛应用的同时,也存在着相关的辐射屏蔽问题,特别是迷宫内剂量的快速估算。该文对当前典型的迷宫内中子及感生γ光子剂量当量的计算方法进行了汇总,将其应用于多折迷宫的计算案例中,并与基于MCNP(Monte Carlo N-particle transport code)的Monte Carlo模拟值进行对比。结果表明:这些计算方法基本能够较为精确的估算迷道内不同点的中子和感生γ光子剂量当量,与Monte Carlo模拟值的偏差在1个数量级以内,但可能会低于模拟值。在实际应用中,可通过乘以安全系数以防止剂量低估。
作者机构：
[于涛; 李志锋; 刘紫静; 谢金森; 张庚] School of Nuclear Science and Technology, University of South China, Hengyang, 421001, China;[谢金森] China Institute of Atomic Energy, Beijing, 102413, China
通讯机构：
School of Nuclear Science and Technology, University of South China, Hengyang, China
摘要：
With the dispersion relation derived for the geodesic acoustic mode in toroidally rotating tokamak plasmas using the fluid model, the effect of the toroidal rotation on the collisional viscous damping of the geodesic acoustic mode is investigated. It is found that the collisional viscous damping of the geodesic acoustic mode has weak increase with respect to the toroidal Mach number.
摘要：
The collisional damping of the geodesic acoustic mode (GAM) is analytically investigated in toroidally rotating tokamaks by using the gyrokinetic equation. It is found that the toroidal rotation could decrease the collisional damping of the GAM in the small safety factor region and increase the collisional damping of the GAM in the large safety factor region at low ion collision rate; while at high ion collision rate, the toroidal rotation will increase the collisional damping of the GAM with arbitrary safety factor. Furthermore, the change quantity of collisional damping rate of the GAM due to the toroidal rotation at high collision rate is larger than that at low collision rate.
摘要：
The radioisotope production has a crucial role in medical diagnosis and therapy. In this work, we investigated the possibility of obtaining radioisotopes of medical interest through photo-neutron reactions using the highintensity γ beams at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility. The specific activity for three benchmark radioisotopes, 99Mo/99mTc, 186Re and 225Ra/225Ac, was obtained as a function of γ-beam energy, target geometry and irradiation time. Optimization for the generation of these radioisotopes at ELI-NP was investigated. We estimated that a saturation specific activity of the order of 1-2 mCi/g could be obtained for a thin target (radius 1-2 mm, thickness 1 cm) and for a conservative γ-beam flux of 1011 s-1. The ELI-NP, based on these estimations, could provide the possibility for the production of certain radioisotopes in sufficient quantities for nuclear medicine research.
摘要：
The detection efficiency of electrostatic collection radon monitors is influenced by the humidity of the air in the collection cell. This is due to the recombination of positively charged 218Po with OH− ions, whose concentration depends on humidity. A novel design of an electrostatic collection cell, in which the air pressure in the cell is less than the atmospheric pressure, is proposed to eliminate the impact of humidity. As a result of the lower air pressure, the drift velocity of the positively charged 218Po in the electric field increases, so the collection time decreases. A model predicting the collection efficiency of positively charged 218Po in this kind of electrostatic collection cell is presented. Based on the model, if the air pressure in the cell is sufficiently low, the collection efficiency will be approximately a constant and the dependency of the collection efficiency of the positively charged 218Po upon the water vapor concentration can be ignored. This approach can be applied to develop a new radon monitor.
作者机构：
[吕莉; 于涛; 谢金森] School of Nuclear Science and Technology, University of South China, Hengyang;Hunan;421001, China;[余红星; 吴丹; 彭欢欢] Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu;610041, China
通讯机构：
School of Nuclear Science and Technology, University of South China, Hengyang, Hunan, China
作者机构：
[李新霞; 岳东宁; 雷晓晨] School of Nuclear Science and Technology, University of South China, Hengyang, China;[李新霞] Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, China
作者机构：
[青涛; 叶海峰; 张力] School of Nuclear Science and Technology, University of South China, Hengyang, China;[李鹏程; 张力] Human Factor Institute, University of South China, Hengyang, China;[张力] Hunan Institute of Technology, Hengyang, China
作者机构：
[Chen, You; Gong, Xueyu; Yu, Jun] Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.;[Gong, Xueyu] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Yu, Jun] U;Univ South China, Sch Math & Phys, Hengyang 421001, Hunan, Peoples R China.
关键词：
tokamak plasma;zonal flow;turbulence
摘要：
With the nonlinear dispersion relation derived, excitation of low frequency zonal flow by drift waves is examined in tokamak plasmas with toroidal rotation. It is shown that the growth rate of the low frequency zonal flow is decreased by the frequency shift of the geodesic acoustic mode and is increased by the additional nonlinear terms with toroidal rotation velocity. If the amplitude of the pump drift wave is greater than the threshold value, which is the function of the Mach number of the toroidal rotation, the toroidal rotation increases the nonlinear growth rate, otherwise, it decreases the nonlinear growth rate. There is always a finite nonlinear growth rate of the low frequency zonal flow if only there is a finite amplitude of the pump wave in tokamak plasmas with a finite velocity of the toroidal rotation.
作者机构：
[Zhang, Li; Zou, Yanhua] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Zhang, Li; Zou, Yanhua] Hunan Inst Technol, Inst Human Factors Engn & Safety Management, Hengyang 421002, Hunan, Peoples R China.;[Zhang, Li; Li, Pengcheng] Univ South China, Human Factor Inst, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Zhang, Li] H;Hunan Inst Technol, Inst Human Factors Engn & Safety Management, Hengyang 421002, Hunan, Peoples R China.
关键词：
Digital main control room;Dynamic network model;Human performance;Reliability forecasting;Situation assessment
摘要：
With the technical development of computer hardware and software, digitalization is a trend in large-scale complex systems such as nuclear power plants (NPPs). It changes the way main control room (MCR) operators interact with systems. Faced with these technical changes, operators need to continue improving their situation assessment (SA) reliability level. In addition to evaluate operators' SA reliability, managers and shift supervisors also want to forecast their SA reliability level. There have been many studies with respect to operators' SA, but most of them are static analysis method and cannot be applied to predict operators' SA reliability. So, on the basis of different forecasting approaches and observation data, how to predict the operators' SA reliability level has became a problem that many analyst interest in. In this paper, first we identified the influence factors associated with SA reliability, and then we developed the SA reliability model, finally we proposed a reliability forecasting model by integrating time series forecasting method with dynamic network model (DNM). Our experiment verification focused on steam generator tube rupture (SGTR) event, using the forecasting model, we demonstrated how to predict operators' SA reliability during the course, and the prediction results are consistent with measurement results. (C) 2015 Elsevier Ltd. All rights reserved.
