开关放电分散性对FLTD模块输出的影响模拟

建立了包含开关放电分散性的电路模型,模型通过电压控制开关和自击穿开关模型的结合,可对开关抖动及支路间放电的相互影响进行模拟,利用研制的300kA单级直线型变压器驱动源(FLTD)模块进行了实验验证,模拟结果与实验相吻合。进而针对设计的20支路FLTD模块建立了电路模型,模拟分析了模块支路开关放电分散性对输出电流峰值和上升沿的影响,模拟结果表明,开关抖动小于5ns时对模块输出影响较小。     

触发时序对直线型脉冲变压器输出参数的影响

 利用通用电路模型程序Pspice,建立了包含60级感应腔串联的单路直线型脉冲变压器（LTD）电路模型,次级传输线采用去离子水绝缘,计算分析了感应腔触发时序对LTD输出参数的影响。结果表明,控制触发时序能够显著改变LTD型驱动源的输出参数。当控制触发时序使得各级感应腔内的开关在闭合前承受一定过电压时,LTD输出电流比单级感应腔同等条件下的输出电流具有更短前沿和更高幅值。假定LTD开关过压击穿电压为400 kV,通过触发时序的优化可提高LTD装置输出性能：前沿从56.5 ns减少至12.5 ns,峰值从1 018 kA提高至1 340 kA。     

“神龙二号”直线感应加速器加速腔电路模拟

针对神龙二号直线感应加速器所采用的非晶磁芯感应加速腔，建立了能够兼顾结构参数和磁芯性能的加速腔电路模型。对与加速腔结构相关的各集总电容参数进行了计算，并通过模拟波形与实验电压电流波形的对比，确定了加速腔磁芯模块的参数设定，实现了对非晶磁芯感应加速腔脉冲励磁过程较为准确的模拟。通过电路模拟，可以得到脉冲励磁时加速腔各部分的电压电流分布，为加速腔的结构优化和故障原因分析提供了有效的手段。     

铁氧体磁芯感应加速腔模型

 针对铁氧体磁芯,建立了以多层有损传输线为基础的同轴感应加速腔物理模型,并在短脉冲励磁条件下,通过低压及高压实验,结合PSpice电路模拟,对模型的准确性进行了验证,并由此间接推算出了铁氧体磁芯在不同情况下的平均脉冲磁导率和介电常数。实验和模拟结果显示,该模型能够准确地反映铁氧体磁芯感应腔在脉冲励磁下的动态物理过程,为感应加速腔实验结果分析、结构优化设计及磁芯性能选取提供了准确有效的方法。     

3 MV感应电压叠加器的磁感应腔研制

 根据脉冲驱动源和负载参数,提出了3 MV感应电压叠加器磁感应腔的设计指标为1.2 MV/70 ns。由感应腔的电流传输效率和真空同轴线绝缘要求,确定了磁芯的几何尺寸;研制了矩形比为0.5的预退火非晶磁环,明确磁环数量不少于6只;在30 T/s时,实验测量的最大脉冲相对磁导率与饱和波模型计算结果相当;估算磁感应腔的等效激磁电感约为7.3 μH,涡流损耗电阻约为139 Ω。根据临界击穿场强的经验公式,采用电场数值分析方法,确定了磁感应腔的电气结构;实验验证了磁感应腔设计有效性;建立了基于磁感应腔的3 MV感应电压叠加器全电路模型,阳极杆箍缩二极管电压、电流计算波形,与实验结果基本相符。     

基于频率失谐的光混沌同步开关的特性研究

针对实验报道的光混沌同步开关现象,建立了基于半导体激光器的光混沌同步开关的理论模型.利用该模型,数值模拟了不同外腔反馈强度和注入强度下的光混沌同步开关特性.结果表明：固定外腔反馈强度,不同注入强度下的混沌同步开关的对比度和宽度均不同;当注入强度与外腔反馈强度相同时,开关的对比度达到最大值;进一步地,当外腔反馈强度和注入强度同步增强时,混沌同步开关的对比度和宽度均单调增大. 关键词： 光混沌同步开关 半导体激光器 频率失谐 外腔反馈     

强流直线感应加速腔微波特性

 介绍了确定不同加速间隙形状和设计结构的强流直线感应加速腔微波特性的方法,即确定频域中加速腔横向阻抗值的方法,包括数值模拟和实验测试。 横向阻抗测试实验中采用了两种测试方法:一种为同轴线束流模拟法,另一种为对加速腔形状因子的测试。实验中测试了3种不同的腔型,并和数值模拟结果进行了比较。两种横向阻抗的测试方法所得结果都与计算结果基本符合,从测试过程的繁简程度和多次实验结果的重复性来看,对于强流直线感应加速腔来说,形状因子值测试方法优于双芯同轴线束流模拟法。实验测试和数值模拟结果显示,确定直线感应加速腔横向阻抗值,测试实验和数值模拟是相辅相成的,缺一不可。     

快前沿直线脉冲变压器单级模块开关触发时延分散性实验研究

针对12支路并联的快前沿直线脉冲变压器单级模块,给出了模块的电路结构和关键器件参数,实验获得了12只多间隙气体开关的自击穿特性和触发特性。同时,还给出了快前沿直线脉冲变压器模块输出电流的初步实验结果,工作电压150 kV时,次级短路放电电流幅值为235 kA,电流前沿88.2 ns（10%~90%）。次级带0.58 负载情况下,输出电流幅值114.5 kA,电流前沿88.9 ns（10%~90%）。利用微分环测量了12只开关的触发时延分散性,结果表明100次实验开关触发时延分散性近似符合正态分布,开关触发时延分散性对输出电流的影响不大,电流幅值和前沿的标准偏差分别小于2.0%,4.0%,电流波形的畸变主要以平顶为主。     

Rimfire开关电路模型

建立了Rimfire开关的串联间隙电路模型,将开关所有的杂散电容都包含在内,结合火花通道的传导特性,以PSpice软件为计算平台,对一个700 kV Rimfire型开关进行了模拟。由于开关所有间隙都具有独立的时间变化参数,因此串联间隙电路模型不但可以在宏观上表现出开关的特性,而且能够模拟开关任一部分的时变电压和电流,进而分析开关的内部工作过程。模拟结果表明:激光触发间隙导通而自击穿间隙不导通时,作用在开关上的总电压超过700 kV;开关正常工作时,作用在所有间隙上的电压均高频振荡衰减。     

低压重频感应加速组元参数分析

针对脉冲源+传输线+感应腔和储能电容+固态开关+感应腔两种常见的脉冲感应组元结构,对相同感应腔的腔压波形进行了实验对比和理论分析,推导出了不同组元结构下感应腔中磁芯回路电感量、匹配电阻阻值和感应脉冲幅度间的关系表达式,分析对比了两种组元结构下感应腔电感量和电阻值变化对腔压平顶影响的程度和差异,为低压重频脉冲感应加速组元的参数选择和优化提出建议和判据。     

Squeezing effect of the cavity field in the two-atom Jaynes-Cummings model

Authors investigate the model that two two level atoms interact with a single mode cavity. The formulation of the time evolution operator for the two atom Jaynes Cummings model is presented by the bare states approach. Besides, squeezing effect of the cavity field is studied and some novel features are obtained.     

Theoretical Study of Millimeter Wave Harmonic Oscillator Stabilized with a Transmission Cavity

An equivalent circuit model of millimeter wave second harmonic oscillator stabilized with a transmission cavity has been proposed for constructing analytical formulations between performance parameters of the oscillator and parameters of the circuit. The model consists of an equivalent circuit of fundamental wave and that of second harmonic wave. Each of the circuits comprises circuit models of main cavity, transmission waveguide, and transmission cavity. Absorbing material placed between the transmission waveguide and the transmission cavity can suppress additional resonances originated from transmission cavity. The behavior of the second harmonic oscillator can be effectively described by the circuit model. Furthermore, based on this model, mechanical tuning characteristics have been studied at first, and then analytical formulas for quality factor and efficiency depending on circuit parameters have been derived. The circuit parameters can be conveniently extracted by electromagnetic field simulation. Hence the formulas exhibit both compact form and enough accuracy. Thereafter, general rules of performance parameters varying with circuit parameters have been deduced for the harmonic oscillators. Then some design considerations have been derived according to the corresponding analysis. The equivalent circuit model is useful for designing and adjusting millimeter wave second harmonic stabilizing oscillator with a transmission cavity.     

The two—atom Jaynes—Cummings model‘’s dynamic properties

The model of two two-level atoms interact with a single-mode cavity was investigated.The formulation of the time evolution operator for the two-atom Jaynes-Cummings model is Pressented by the bare-states approach.Besides,the time evolution of the two-atom common population probabilities is studied,and some novel fearures are obtained.     

利用等效电路模型计算耦合腔行波管注-波互作用

通过研究Curnow等效电路模型,得到进行单腔计算的矩阵方程,进而获得线路场方程, 结合运动方程和空间电荷场方程,从而推导出耦合腔行波管一维注波互作用非线性理论模型. 该理论能计算任意的切断、跳变、渐变等结构以及多信号模拟.利用该理论编制的软件计算了 59 GHz-64 GHz耦合腔行波管AM-PM相位失真,三阶互调以及五阶互调分量. 同时模拟得到了59 GHz-64 GHz带内饱和输出功率分布,理论结果与热测结果误差在5%以内.     

多腔场猫态制备新方案研究

我们提出了一个制备多腔场薛定谔猫态的新方案.在这个方案里,我们需要一个两能级原子和几个铜的单模腔.其中,原子跃迁频率与各腔场频率是大失谐的.将原子同时注入几个腔中,原子与各腔同时发生相互作用.系统按大失谐情况下J-C模型演化.着重讨论了三腔场薛定谔猫态的制备,我们的方案可以很容易被推广到多腔场薛定谔猫态的制备.     

Simulation Investigation of Millimeter Wave Varactor-tuned Transmission Cavity-stabilized Oscillator

A new circuit configuration for millimeter wave varactor-tuned transmission cavity-stabilized oscillator has been proposed in this paper. Compared to conventional varactor-tuned reflection cavity-stabilized oscillator, in this configuration, a high quality factor transmission cavity directly coupled to varactor diode is employed to improve the performances of the oscillator. The operation frequency of this oscillator can be tuned by varying the resonant frequency of the transmission cavity through changing bias voltage of the varactor diode. An equivalent circuit model for the oscillator has been presented in order to theoretically investigate the performance characteristics of the oscillator. On the basis of this model, electrical tuning characteristics have been studied. Mode jumping phenomena during electrical tuning process have been analyzed for obtaining stable operations of the oscillator. The analytical formulae of quality factor and efficiency have been derived in terms of relevant circuit parameters. Particular emphasis has been paid on several circuit parameters which have a substantial impact on circuit performance. Some design considerations have been pointed out according to the simulation results, which are useful to the design and fabrication of this type of oscillators.     

耦合腔链等效电路模型计算加速管场分布

介绍利用耦合腔链等效电路模型计算加速管场分布的原理和方法. 把加速腔链等效为谐振电路, 通过求解回路方程组, 并引入分流阻抗等物理参数, 可计算加速腔链整管的电磁场幅值和相位分布. 这一计算方法对加速管动力学设计和加速管几何参数设计有很好的指导意义, 并在16MeV返波加速管设计调试过程中得到了应用和验证.