Power Absorption of High Frequency Electromagnetic Waves in a Partially Ionized Plasma Layer in Atmosphere Conditions

We have studied the absorption, reflection, and transmission of electromagnetic waves in an unmagnetized uniform plasma layer covering a metal surface in atmosphere conditions. Instead of the absorption of the electromagnetic wave propagating only once in previous work on the plasma layer, a general formula of total power absorption by the plasma layer with an infinite time of reflections between the atmosphere-plasma interface and the metal surface has been derived for the first time. Effects of plasma parameters, especially the dependence of the fraction of positive lons, negative ions and electrons in plasmas on the power absorption processes are discussed. The results show that the existence of negative ions significantly reduces the power absorption of the electromagnetic wave. Absorptions of electromagnetic waves are calculated.     

EAST离子回旋系统液态相移器的理论设计

对EAST离子回旋系统液态相移器的原理进行了理论分析和计算,结果表明:利用液态相移器可产生相位差,从而可用离子回旋波进行电流驱动。另外,液态相移器也可与单支节液态调配器结合使用,构成传输线阻抗匹配系统。     

A Ray-Tracing Analysis of ICRH in Tokamaks

Power deposition profiles generated by Ion Cyclotron Resonance Heating （ICRH） in non-circular tokamaks are studied using a ray-tracing technique. The simulation results for the Experimental Advanced Superconductor Tokamak （EAST） D-shaped plasma are presented. It is indicated that the spatial distributions of plasma parameters （plasma density, species temperature, minority ion concentration, etc.） have an significant influence on the power deposition profiles. The findings may be highly useful to the planned plasma heating and experiments in EAST.     

100 MeV强流质子回旋加速器的调试

〗中国原子能科学研究院研制的100 MeV强流质子回旋加速器是国际上最大的紧凑型强流质子回旋加速器,取得了多项先进束流指标。截至2018年底,该加速器完成了分系统、整机调试,开展了多项物理实验,已稳定运行2 000 h以上。本文将重点介绍100 MeV强流质子回旋加速器的调试过程以及调试中所解决的关键技术问题和调试结果。     

The Effects of Relative Drift Velocities Between Proton and He2＋ on the Magnetic Spectral Signatures in the Plasma Depletion Layer

Magnetic spectrum of the electromagnetic ion cyclotron waves in the terrestrial plasma depletion layer （PDL） are sometimes observed to have a BIF （bifurcated） s...     

回旋加速器束流输运系统离子光学特性分析

为了提高束流在输运系统中的传输效率,改善靶点的束斑特性,本文用TRANSPORT程序对四川大学回旋加速器束流传输系统的光学特性进行了计算和分析。 TRANSPORT是采用矩阵方法计算带电粒子束在输运系统中光学特性的通用计算机程序,并能利用非线性最小二乘法和耦合系数方法对系统参数实行优化,广泛用于束流传输系     

ZL－I散射式自动跟踪γ料位计的研制

本文描述了一台散射式自动跟踪γ料位计。它的主要技术指标是：跟踪范围４ｍ；跟踪最大速度６ｍｍ／ｓ；对壁厚２０ｍｍ钢板容器充满沥青介质的测量精度±１ｍｍ。     

电子回旋波在非圆截面托卡马克等离子体中的传播与功率沉积

通过求解等离子体平衡方程、波迹方程和准线性Fokker-Planck方程,数值模拟了电子回旋(EC)波在非圆截面托卡马克等离子体中的传播轨迹和功率沉积。模拟结果表明:当EC波从顶部发射时,相比于圆截面的EC波波迹,非圆截面的波迹会向等离子体弱场侧偏移,增大等离子体中心电子密度,波迹也会偏向弱场侧,相应的波功率沉积有所降低;当EC波O模从中平面弱场侧发射时,随着平行折射率的增大,波迹弯曲幅度变大,增大到一定数值时会折回弱场侧穿出,波功率沉积随极向发射角的增大而降低,环向发射角约取10°时,波功率沉积达到最大。     

70 MHz回旋加速器谐振腔高频性能的数值研究

介绍了用数值模拟手段设计加速腔体的方法。在设计70MHz回旋加速器谐振腔的过程中，为满足回旋加速器磁铁的结构要求，对高频频率、Q值等高频参数进行了研究。在设计阶段，应用基于有限元方法的程序对高频实验进行模拟计算。回旋加速器腔体的初步设计结果将用于最终物理设计和工程设计。     

OPERATING POINT AND STRIPPING EXTRACTION CALCULATIONS FOR CYCLONE 10/5

By using the magnetic field map, equilibrium orbit, operating point of v r and v z and beam trajectories after stripper for Cyclone 10/5 have been calculated. The positions of two strippers and two targets have been determined. The numerical simulation is consistent with experimental tests.     

FDTD Numerical Simulation of Absorption of Microwaves in an Unmagnetized Atmosphere Plasma

Numerical simulations based on the finite-difference-time-domain （FDTD） approximation to multi-fluid equations for positive ions, negative ions and electrons are used to study high frequency electromagnetic wave propagation and absorption in an unmagnetized plasma layer. The interaction between the incident high frequency wave and the plasma layer shows that the existence of negative ions and the nonlinear effect reduces the power absorption capability of the plasma. Parameter dependences of the effects are calculated and discussed.     

ECR离子源微波窗损伤机理研究

强束流下微波窗损坏是限制2.45 GHz电子回旋共振（ECR）离子源寿命的主要原因,为延长离子源使用寿命,对ECR离子源微波窗损伤机理进行了研究。利用有限元软件分别计算了Al₂O₃陶瓷微波窗在微波、等离子体和回流电子束作用下的温度及应力分布。计算结果表明,在微波和等离子体作用下,微波窗边缘处应力最大,在电子束作用下,微波窗中心位置应力最大。增强水冷效果可降低微波和等离子体对微波窗的影响,增加Al₂O₃陶瓷微波窗表面氮化硼（BN）的厚度可降低电子束的影响,从而减少微波窗损坏概率,延长离子源寿命。     

Preservation of transmission probabilities in the method of characteristics

An efficient calculation scheme for the method of characteristics, which allows coarser ray separation width, is newly proposed. Effective lengths of characteristics lines are evaluated from the viewpoint of preservation of transmission probability in the present method. The effective lengths to preserve transmission probabilities can be rigorously estimated through detailed numerical integrations. However, calculation and storage of all effective lengths is inefficient since the transmission probabilities depend on many parameters such as azimuthal angle, polar angle, position of characteristics line, and total cross section. To resolve this issue, in this paper, the analytical equations for the effective lengths are derived from an assumption that distribution function of actual characteristics lengths can be expressed by a linear function. The new approach introduced in this paper is named as transmission probability preservation through linear approximation (TPPL). Verification results indicate that accurate results can be obtained by the TPPL even if ray separation width becomes coarse.     

100MeV强流质子回旋加速器主磁铁电磁力的数值模拟

本工作研究计算中国原子能科学研究院目前正在设计、建造中的100MeV强流质子回旋加速器CYCIAE-100主磁铁电磁力。计算中选用虚位移法和麦克斯韦应力张量法两种方法。在利用电磁场三维有限元分析程序计算得到紧凑型等时性回旋加速器主磁铁电磁场的基础上,先采用虚位移法估算电磁吸力,然后基于麦克斯韦应力张量法在MATLAB环境下编写数值计算程序,详细研究磁极和磁轭受到的电磁吸力。两种方法的计算结果接近。计算得到的主磁铁磁极间吸力大于磁极与盖板间吸力,二者之差由磁极和盖板间的螺栓承担。电磁力的计算结果为主磁铁结构变形计算和结构方案选取提供了依据。