A Numerical Study of the IEMP Generated in a Cylindrical Cavity

In this paper we present the results of a numerical calculation for the IEMP generated in a two-dimensionl cylindrical cavity together with the plotted waveforms. A study is made on the dependence of the duration, amplitude and polarization of IEMP on the rise rate, maximal dose rate fmax of the gamma rays, the length L and radius a of the cylindrical cavity as well as the air density ?r.     

低能注量X射线辐照下圆柱腔内辐射环境及IEMP的模拟研究

通过MCNP程序模拟计算了低能注量X射线辐照圆柱腔外端面并透射进入腔体时,腔内各作用面的综合辐照环境及电子发射参数。结合3维粒子模拟（PIC）程序,对多发射面作用下圆柱腔内电磁场和粒子分布进行了模拟计算,并与仅存在上端面电子发射时的电磁场结果进行对比。结果表明,在实际情况下,圆柱侧壁和下端面会发射大量电子,能将上端面中心处的轴向电场强度增大至仅上端面发射电子时的2倍,而由于此时腔内多发射面作用下电流方向的复杂化,磁场强度则略微减小。同时,比较了由MCNP计算得到的前向散射电子能谱和部分文献采用的近似能谱,分别提供电子发射速度时内电磁脉冲（IEMP）的电场强度波形。结果表明,能谱的改变会对电磁场带来极大的改变,故建议通过相关蒙特卡罗（MC）程序计算IEMP电子发射能谱。     

The Damage Susceptibility of Integrated Circuits to a Simulated IEMP Transient

Recent investigations have been directed toward gaining insight into the effect of electrical pulse overstressing in integrated circuits, especially simple gates and bipolar LSI arrays. In order to determine the effect of ionizing radiation on the pulse-power failure susceptibility levels of small scale, monolithic, junction-isolated integrated circuits (simple gates), an experimental study was undertaken such that device failures could be induced in a simulated EMP or IEMP environment. The device types investigated included low- and high-power, quadruple, dual-input, positive NAND TTL gates. Permanent damage levels for these devices were determined for both positive and negative-polarity sub-microsecond pulses, introduced into the input, output and bias terminals of active devices, some of which were simultaneously irradiated by gamma radiation. The radiation dose rates ranged from 1 × 1010 to 5 × 1010 rads(Si)/sec. The failure susceptibility level of a device was found to depend uniquely upon the ionizing radiation, the device terminal subjected to the electrical stress pulse, and the polarity of the pulse. The data for device failures in the simulated EMP environment agree with the existing thermal-failure models characterized by P = Atm, where P is the power required to induce failure and t is the time to failure. In a radiation environment it was observed that initial ionization tends to reduce the magnitude of the constant A and shifts the time to failure t from the constant-energy regime (m = -1) to another.     

空腔电离理论发展概述

简述了空腔电离理论的基本原理及其在辐射剂量学中的地位;介绍了Bragg—Gray理论、Spencer—Attix理论、Burch理论、Burlin模型、Kearsley模型、等效电子源理论等空腔电离理论及各种理论的适用范围;同时,介绍了用蒙特卡罗方法(EGS4程序)对不同理论及模型的计算结果。     

Calculation of Spencer-Attix Cavity Theory Correction Factor of Different Cavity Volumes

正For purpose of obtaining a lower absolute measurement limit ofγ-ray air kerma,a larger graphite-walled cavity ionization chamber is usually expected.Although this method is feasible,it is necessary to consider the effect of the actual cavity on the results calculated by cavity theory.In order to investigate the accuracy of the results     

空腔理论在固体剂量计中的应用

在Burlin空腔理论基础上提出了1个经修改后可适用于兆伏级X(γ)能量固体剂量计的新空腔理论。它通过Monte-Carlo方法分别计算固体剂量计空腔内的初级光子粒子注量和散射光子粒子注量及它们相应产生的次级电子粒子注量，并按空腔尺寸所对应的电子射程，把高能和低能光子分开，计算初级光子和散射光子沉积在固体剂量计灵敏体积中的能量，即吸收剂量。为验证该空腔理论，用半导体固体剂量计在6MV医用电子直线加速器上进行了水模体输出因子测量，并模拟相同测量条件用新空腔理论对水模体输出因子进行了理论计算，其测量结果与计算结果在0.5%内符合。     

Theory and Experiment with a Gas Stabilized Constricted Arc

Measurements of voltage gradient and static pressure distribution in the constrictor of a gas stabilized constricted arc discharge are reported. These and previously obtained data yielding the column diameter are used to compare the behavior of this discharge with laminar column theories. Significant disagreement are found, and it is concluded that the discharge represents an inlet flow region. A qualitative model is presented of the physical processes occuring in this inlet region. The implications for arc heater efficiency of this model and of the data are discussed.     

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。     

Neutron Radiation Effects on MOS Fets: Theory and Experiment

The effects of a pure neutron environment on Metal-Oxide-Semiconductor Field Effect Transistors (MOS-FET) is studied. A model for neutron-produced ionization in the oxide layer is presented. The energy partition between atomic displacement and electronic ionization processes in the nuclear scattering interaction is calculated and compared to the Lindhard model. It is shown that the neutron ionization causes a positive charge buildup in the oxide similar to a gamma ionization charge buildup. It is also shown that fast neutrons produce significant ionization energy which can become the major cause for ionization damage in a mixed neutron-gamma environment such as a nuclear blast. Specific experimental results are given for commercial and experimental MOS-FETS. The experimental technique used in achieving an almost pure neutron environment is described. Finally, an ionization dose equivalence for fast neutrons in SiO2 is given and compared to experimental values. This relation should prove useful in future studies of ionization damage in SiO2 subjected to a neutron-gamma environment.     

西安脉冲反应堆辐照腔参数理论计算分析

介绍了西安脉冲反应堆辐照腔参数的理论计算模型和计算程序。计算了辐照腔中的快中子（E≥0.1MeV)注量和辐照腔屏蔽外表面处的当量剂量率，理论计算与实测值比较表明，二者符合很好。     

核电厂操纵员可靠性理论模型与实验研究

采用核电厂模拟器作为研究平台,以人的认知可靠性模型为参考,运用两参数威布尔分布对原有理论模型进行改造,建立了中国核电厂操纵员可靠性研究理论模型。应用该模型对核电厂操纵员可靠性进行研究,并与国外同类研究成果进行了比较,得到了一致的结果。     

Axial Flow through the Wall-Constricted Direct-Current Arc-Comparison of Theory and Experiment

The basis of a simple theoretical analysis by Stine and Watson of the behavior of a wall-constricted plasma generator is considered. Experimental results are presented for a plasma generator designed from gas transport properties and theory. In general the agreement between theory and measured performance of the plasma generator indicates that the underlying physical principles are reasonably well understood.     

基于孔洞长大理论的多轴蠕变设计模型及其工程应用

多轴蠕变是高温构件失效的重要原因,工程设计中必须予以考虑.本文介绍了以孔洞长大理论为基础的多轴蠕变设计方法;探讨了孔洞长大的基本原理;讨论了基于该理论的5个常用模型;分析了这些模型在R5、ASME III、RCC-MR 及VGB-R 509L 中的应用,指出了高温构件多轴蠕变设计的困难,并对进一步的工作提出了建议.     

The Efficacy of Hydrodynamic Compression Using a Conical Cavity

A technique for controlled hydrodynamic compression of gases using a conical cavity driven by liquid metal was proposed by Lei (2016) as a convenient, low-cost, repetitive instrument to achieve a very high compression ratio of up to \(10^9\). If the compression is fully adiabatic, such compression will raise the gas temperature by a factor of \(10^6\) for monoatomic gases. In this paper, we develop a 0-D semi-analytic model to examine in detail the adiabatic assumption, taking into account in particular the physical processes of dissociation, ionization, radiation, and energy exchange between the compressed gas and the wall, and provide an assessment of the temperature of the gas or plasma that may be attainable using the technique. The numerical results show that these physical processes drastically lower the temperature attainable. Nevertheless, the results still indicate that final gas temperature of more than 10 eV, and volume-compression-ratio more than \(10^6\), are still attainable that might enable a number of interesting applications. The modeling results also revealing some interesting effects of partially ionized gases under high ratio of compression.     

EMP Response of a Cavity: Field Generation within a Lossy Dielectric Cylinder Excited by a Radiation Pulse

A transient electromagnetic field problem is solved for a finite length cylindrical cavity bounded by perfectly conducting walls. The cavity is filled with a homogeneous lossy dielectric material. Analytic solutions for the relevant components of the electric and magnetic fields generated by an axially propagating current pulse are presented. Results obtained for various sample problems are discussed.     

CYCIAE-100紧凑型回旋加速器低温板排气系统理论和实验研究

根据CYCIAE-100紧凑型回旋加速器的结构特点,设计了一套大抽速低温板排气系统,插入到CYCIAE-100紧凑型回旋加速器主磁铁谷区中,该套排气系统将使CYCIAE-100紧凑型回旋加速器加速腔内真空度好于5×10^-6 Pa。目前该套低温板排气系统已设计完成,用Monte-Carlo方法对其进行了优化,并进行了加工、安装和初步调试,调试时低温冷板上温度达19 K,CYCIAE-100紧凑型回旋加速器加速腔内真空度达到8×10^-6 Pa。     

A Comparison of Heavy Ion Sources Used in Cosmic Ray Simulation Studies of VLSI Circuits

A comparison has been made between the heavy ions from the ALICE cyclotron and Californium-252. The results of SEU cross-section measurements support the use of the CASE system (Californium-252 Assessment of Single-event Effects) to simulate cosmic ray effects in VLSI circuits.     

核电厂操纵员认知可靠性研究模型的选择与实验

本文采用核电厂模拟器作为研究平台 ,利用国际上流行的人的认知可靠性模型作为参考 ,运用两参数威布尔分布对三参数威布尔分布进行改造 ,建立了具有特色的中国核电厂操纵员可靠性研究理论模型 ,并应用该模型对核电厂操纵员可靠性进行了深入研究 ,与国外同类研究成果进行了比较 ,得到了一致的结果 ,该研究的进行可对核电厂的安全运行起到有益作用。     

Study and Design of a High-Frequency Interaction Cavity for a 140 GHz Megawatts Gyrotron

The gyrotron is one of the most promising high-power millimeter-wave sources for electron cyclotron resonance heating(ECRH) in controlled thermal nuclear fusion experiments.In this paper,the design of a high-frequency interaction cavity of a 1 MW/140 GHz gyrotron is described in detail.The cavity is designed by using eigen mode analysis and radio frequency(RF) behavior calculation.Rounded transitions at the input and output tapers are designed for reducing mode conversion.With the obtained cavity structure,non-linear self-consistent equations are adopted to calculate its output power and efficiency.A particle-in-cell(PIC) method is used to simulate the beam-wave interaction process for obtaining the resonant frequency and output power of the cavity.The PIC simulation results match considerably well with the results obtained by the non-linear self-consistent calculation.The cavity is currently under construction and will be integrated with other components for overall testing.     

基于蠕变孔洞长大理论的高温构件蠕变强度设计准则研究

在分析高温构件蠕变失效微观机理的基础上,提出了基于孔洞长大理论的蠕变应变设计准则和蠕变应力设计准则.定义了蠕变等效应力和蠕变等效应变,探讨了蠕变许用应力和蠕变许用应变的确定原则.这些设计准则考虑了蠕变失效的微观机理和时间相关性的影响,能给出比传统设计方法更为稳定和合理的设计结果.分析了在蠕变强度设计上存在的困难,并提出了相应的建议.