共查询到19条相似文献,搜索用时 73 毫秒
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为保护电子设备不受高功率微波损坏,在矩形波导中嵌入等离子体限幅器。计算了不同气体的微波击穿场强随气体压强以及微波频率的变化规律。在高气压条件下(1 333~133 320 Pa),气体击穿场强随气压增大而增大,在计算的4种气体中Ne的击穿场强最小;低气压条件下(1.333 2~133.32 Pa),气体击穿场强随气压增大而减小,且Xe具有最小击穿场强。高气压条件下气体的击穿场强明显高于低气压下的击穿场强。计算结果表明:当填充133.32 Pa的Xe时,限幅器能够在约30 km范围内,有效地防护10 GW级高功率微波对电子设备的损坏。 相似文献
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用冷流体模型推导了轴对称条件下,多成份、多界面、小横向束速度、束密度依赖于轴半径的束-等离子体系统中纵向电磁场所满足的一般方程、横向电磁场及其边界条件的一般表达式以及柱形金属波导中均匀束一等离子体系统的色散关系,分析了均匀单电子束、双电子束-等离子体系统中存在的电磁波模式以及单电子束系统的Cerenkov微波辐射的增长率和频移。 相似文献
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基于PIN限幅器的等效电路模型,构建了PIN限幅器HPM效应ADS等效电路仿真模型,利用HPM注入实验和等效电路仿真相结合的方法,研究了单个微波脉冲作用下PIN限幅器的响应规律,获取了HPM作用结束后限幅器限幅持续时间与注入脉冲功率、脉宽的对应关系,并对限幅器的限幅持续过程进行了分析。仿真与实验结果表明:PIN限幅器限幅持续时间随着微波脉冲功率和脉宽的增大而变大,实验和仿真结果趋势一致,该研究使用的ADS等效电路模型可以应用于PIN限幅器的高功率微波瞬态响应特性分析研究。 相似文献
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基于PIN二极管电热自洽耦合模型,构建了两级PIN限幅器高功率微波(HPM)效应电路模型。根据模拟模型设计加工了两级限幅器实验样品,限幅器输入、输出特性注入实验数据与模拟计算结果基本一致,验证了多级限幅器模型的有效性,表明该多级PIN限幅器模型能够应用于HPM效应模拟。针对不同HPM波形参数进行了HPM效应模拟,计算结果表明:随着注入功率的增大,脉宽增宽,前级厚I层PIN二极管结温升比后级薄I层PIN二极管结温升要高,因此厚I层PIN二极管更易受到损伤;而频率和前沿参数对结温升影响较小。 相似文献
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基于PIN二极管电热自洽耦合模型,构建了两级PIN限幅器高功率微波(HPM)效应电路模型。根据模拟模型设计加工了两级限幅器实验样品,限幅器输入、输出特性注入实验数据与模拟计算结果基本一致,验证了多级限幅器模型的有效性,表明该多级PIN限幅器模型能够应用于HPM效应模拟。针对不同HPM波形参数进行了HPM效应模拟,计算结果表明:随着注入功率的增大,脉宽增宽,前级厚I层PIN二极管结温升比后级薄I层PIN二极管结温升要高,因此厚I层PIN二极管更易受到损伤;而频率和前沿参数对结温升影响较小。 相似文献
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Limiters play a number of roles in the tokamak operation. It serves primarily to protect the wall from the plasma when there are disruptions, runaway electrons, or other instabilities and also the limiters localize the plasma–surface interaction. In this research, we presented the first results of movable limiter experiments and its effects on the tokamak plasma confinement. For this purpose, we designed, constructed, and installed a movable localized poloidal limiter, and then measured the effects of limiter position on the time intervals of plasma parameters such as plasma density, temperature, and energy confinement time. The results of effects of the movable limiter experiments on plasma confinement. 相似文献
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Maryam Ghasemloo Mahmood Ghoranneviss Ahmad Salar Elahi Mohammad Kazem Salem 《辐射效应与固体损伤》2013,168(1):42-47
In this paper, an emissive-biased limiter (EBL) was designed and fabricated then the magneto hydrodynamic activity was investigated based on Mirnov oscillations and hard X-ray spectroscopy through the tokamak plasma biasing. The EBL is positioned at r/a=0.92, and the biased voltage, which is varied from?250 to 250 V, applied between the head of the emissive limiter and vacuum chamber. Furthermore, the effects of the biased limiter for both negative and positive applied voltages are measured, and the results are compared with cold-biased limiter. As the results of IR-T1 tokamak suggest, in emissive negative polarity, the duration of plasma current is increased, compared with no bias, cold positive and emissive positive polarities. The amplitude of Mirnov fluctuations in emissive negative polarity is larger and more regular, compared with emissive positive polarity. The amplitude of the hard X-ray fluctuation in emissive negative polarity is very low compared with cold negative, cold positive and emissive positive polarities which leads to minimum energy loss. 相似文献
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The experimental findings on the DC and AC breakdown strength of polyethylene/silica nanocomposites are reported and correlated with simulation results on the electric field distribution of possible nanocomposite models. Specifically, the effects of interphase permittivity and interparticle distances on the electric field intensity and the breakdown strength are discussed with the aid of the Finite Element Method Magnetics (FEMM) 4.2 software. The results showed that the presence of the interphase, when assigned a unique interphase permittivity value, led to variations in electric field distributions. The electric field also changed as adjacent nanoparticles separated from each other with different interparticle distances. 相似文献
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A hot limiter biasing system with a simplified fast switch circuit was designed, constructed, and installed on the IR-T1 tokamak, and then the negative voltage applied to a hot limiter inserted inside the tokamak fixed limiter and the plasma current, poloidal, and radial components of the magnetic fields, loop voltage, diamagnetic flux, and the ion saturation currents in the absence and presence of the biased limiter were measured. Results of measurements of biasing effects on the plasma equilibrium behavior and edge plasma rotation are compared and discussed. 相似文献
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基于电磁脉冲对半导体器件效应的电-热多物理场模型,利用Sentaurus-TCAD仿真器建立了PIN限幅器电磁脉冲效应数值模型,研究了不同峰值功率的电磁脉冲作用下限幅器的输入/输出特性,以及大功率电磁脉冲注入PIN器件热损伤阈值与脉冲宽度的关系。模拟与实验结果表明:基于器件热效应影响载流子输运过程的电-热多物理模场型,模拟限幅器在大功率电磁脉冲注入下输入/输出功率的结果与实验结果吻合较好;模拟大功率电磁脉冲注入PIN器件热损伤阈值与脉冲宽度的关系式,与Wunsch-Bell半经验关系式符合较好。 相似文献
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基于电磁脉冲对半导体器件效应的电-热多物理场模型,利用Sentaurus-TCAD仿真器建立了PIN限幅器电磁脉冲效应数值模型,研究了不同峰值功率的电磁脉冲作用下限幅器的输入/输出特性,以及大功率电磁脉冲注入PIN器件热损伤阈值与脉冲宽度的关系。模拟与实验结果表明:基于器件热效应影响载流子输运过程的电-热多物理模场型,模拟限幅器在大功率电磁脉冲注入下输入/输出功率的结果与实验结果吻合较好;模拟大功率电磁脉冲注入PIN器件热损伤阈值与脉冲宽度的关系式,与Wunsch-Bell半经验关系式符合较好。 相似文献
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为研究液态锂在电磁驱动限制器表面的铺展特性,设计了与EAST限制器接口相同的限制器测试平台.该平台运行时真空环境可达10?4Pa,对被测限制器可加热至350℃.在限制器锂回路管道上,利用外部2T水平磁场以及竖直方向施加的最大为200A的直流电流,形成电磁驱动力驱动下的锂液循环回路.测试平台设有顶部和正面两个观察窗,能够... 相似文献