复杂辐射环境与武器装备试验评估

从业内普遍接受的电磁环境和武器装备电磁环境效应概念入手,提出了复杂辐射环境概念,解释了其内涵和意义;围绕军事问题,探讨了辐射环境的基本构成,从辐射来源上突出了水声环境、电磁环境、光学环境和核辐射环境四个剖面,从效应考虑又将其分解为自然辐射环境、自扰互扰辐射环境、背景辐射环境和威胁辐射环境四个剖面,指出了这些剖面的统计独立性;根据辐射环境结构、特性和信息承载效应,定义了辐射环境的复杂度,介绍了辐射对抗的基本原理;指出复杂辐射环境下武器装备试验与评估问题与传统问题一样,仍是个概率统计问题,并且给出了可按环境剖面进行分解的高效简便的试验与评估方法。     

Relativistic corrections to the gravitational radiation of a binary system and the fine structure of the spectrum

Relativistic corrections to the gravitational radiation emitted by a system of two point masses performing a quasielliptical motion are calculated in the Teukolsky formalism. It is shown that the radiation spectrum possesses a fine structure analogous to that of atomic spectra.     

Calculation techniques with the Monte Carlo method in stray radiation evaluation

Some calculation techniques with the Monte Carlo method in stray radiation evaluation such as imaginary covers, domain decomposition, coordinate conversion, principle of weight-equivalent sampling, randomness of radiant characteristic of heat insulating coat are described. Employing these techniques, the stray radiation calculation for a large optical system can be achieved in a personal computer. Taking a satellite-borne optical system, for example, the stray radiation flux and stray radiation environment of the system is obtained. The calculation results present a reference for the design of the optical system.     

基于声辐射模态的有源控制解耦

在声辐射模态有源噪声控制策略框架下,选择压电陶瓷片作为控制作动器。根据前四阶声辐射模态形状特点提出了四种压电作动器位置布置方法。理论分析及数值计算表明,以这种方式布放的压电作动器不仅能有效地降低结构辐射的声功率,而且控制过程中这四组作动器分工明确,从而将控制方程解耦。在控制前几阶声辐射模态声功率时可以将复杂的多输入/多输出控制系统转变为几个简单的、互相独立的单输入/单输出控制系统。      

空间环境对卫星光通信系统性能的影响分析

分析了空间环境对卫星光通信系统的主要影响因素,包括高能带电粒子辐射、太阳辐射、等离子体辐射等环境。分析结果表明,为了有效减小卫星光通信器件的单粒子翻转率,需要对轨道倾角和轨道高度进行优化设计;为了有效抑制太阳辐射,对日俯仰角需要限制在一个很小的变化范围;增大信号发射功率和减小系统跟瞄误差都是提高卫星光通信系统可靠性的有效途径;对等离子体辐射环境来说,300eV以上的中等能量等离子体会严重干扰卫星的正常工作。     

Motion and gravitational radiation of a binary system consisting of an oscillating and rotating coplanar dusty disk and a point-like object

A binary system composed of an oscillating and rotating coplanar dusty disk and a point mass is considered. The conservative dynamics is treated on the Newtonian level. The effects of gravitational radiation reaction and wave emission are studied to leading quadrupole order. The related waveforms are given. The dynamical evolution of the system is determined semi-analytically exploiting the Hamiltonian equations of motion which comprise the effects both of the Newtonian tidal interaction and the radiation reaction on the motion of the binary system in elliptic orbits. Tidal resonance effects between orbital and oscillatory motions are considered in the presence of radiation damping.     

Simultaneous effects of pressure and temperature on the binding energy and diamagnetic susceptibility of a laser dressed donor in a spherical quantum dot

Binding energies and diamagnetic susceptibility of an impurity in a spherical GaAs quantum dot under the simultaneous influence of static pressure, temperature and laser radiation are investigated. Pressure- and temperature-dependent dressed potential which is produced by the combined effects of laser radiation and impurity considerably change the energy spectrum and diamagnetic susceptibility of the system. It is shown that binding energies and diamagnetic susceptibility increase with increasing pressure. Moreover, laser radiation effects on the diamagnetic susceptibility are not significant in comparison with its effects on the binding energy.     

小型旋翼机机载辐射环境监测系统的设计与实现

利用小型旋翼机良好的机动性能和环境适用性,将小型旋翼机与传统的核辐射探测设备相结合,再通过软硬件的开发、无线通讯、GPS定位以及核数据处理技术的应用,研发了一套具有受地形环境影响小、可避免人员受到近距离辐射损伤等优点的机载辐射监测系统。介绍了系统的结构组成、工作原理以及关键技术难点,重点研究了系统关键模块的设计以及剂量率响应线性范围的测定。飞行实测结果表明,该系统可对环境中的放射性实时、准确地测量,可用于日常的辐射环境监测以及失控放射源的搜寻,为核应急提供了一种新方法。     

晶体摆动场辐射及其共振线附近的粒子运动行为

寻找新光源,特别是短波长相干光源引起了人们的广泛注意,利用晶体摆动场辐射作为短波长相干光源是最有可能的方案之一,本文从势和场的观点出发,把周期弯晶产生的离心力视为离心势,将粒子运动方程化为Duffing型Mathieu方程,从能量观点出发讨论了系统的稳定性,用摄动法对共振线附近粒子的运动行为进行了分析;揭示了系统的跳跃现象和不稳定行为,结果表明,系统的稳定性与其参数有关,适当调节这些参数,系统的分叉和不稳定性原则上可以避免。     

Measuring the distribution of particles according to their velocity in accelerator beams on the basis of Cherenkov radiation in the optical and microwave range

Methods for measuring the energy spectra of powerful beams of charged particles and their bunches according to the dependence of the intensity of Cherenkov radiation on the refractive index of the radiator (with and without using of dispersion) are considered. The methods are practically nondestructive. In the case of special demands on the Cherenkov radiation collection system, beam spectra with unknown angular distributions can be measured. Uncharged particle spectra are determined from the secondary charged particles spectra.     

离子通道中相对论电子注的切连科夫辐射

对入射等离子体的相对论电子注(REB)在离子通道中可能产生切连科夫(Cherenkov)辐射的问题进行了论证与研究.利用线性理论分析了离子背景下的注-波互作用关系，导出了系统的色散方程与同步辐射条件.结果表明，系统的电磁不稳定性是由离子通道中TM模与电子注模通过电子注耦合所致，其微观机理是离子对电子注的聚焦.对处于运动等离子体状态下的离子-注系统进行了严格地理论分析，获得了通道内辐射波的频偏与波增长率公式，并通过数值模拟计算讨论了系统有关参数对它们的影响. 关键词： 离子通道 等离子体 切连科夫辐射     

射频场照射下扩展的Solomon方程及射频场的照射对异核体系弛豫速率与NOE的影响

根据WBR理论,采用“改进的矩阵计算方法”,推导出了射频场照射下扩展的Solomon方程,并据此研究了射频场的照射对异核体系各种弛豫速率与NOE的影响,得出了如下结论:1)给出的方程比Boulat和Bodenhausen的方程更准确、更具普遍性,能够具体描述射频场对各种弛豫速率与NOE的影响.2)射频场的照射对纵向与横向弛豫速率的影响甚微,可以忽略,而交叉弛豫速率在射频场的照射下则有一定程度的降低.3)射频场的照射将使NOE变弱,且射频场越强,NOE越弱. 关键词： 核磁共振 Solomon方程 弛豫 射频场     

非平衡态辐射场能量状态参数的表征

本文提出了非平衡态辐射体系的热力学框架,以光子的能量、光子的有效能、光子的熵、光子的特征温度为基础,把辐射热力学体系分解为边界和辐射场进行描述,给出了非平衡态辐射场中辐射能状态参数的表征式,提出了表征任意指定照射窗口的照射辐射特征温度概念,结合照射辐射强度、照射辐射能量等效温度,表征了辐射场的能量强度、有效能和熵等热力学参数。     

Radiation clusters and the active control of sound transmission into a symmetric enclosure

Radiation cluster control is proposed for the purpose of attenuating harmonic sound transmission into a symmetric enclosure using error signals derived from structural vibration sensors. The approach falls into a category of middle authority control, which is between LAC (low authority control: structural modal control) and HAC (high authority control: radiation modal control), possessing the benefit of practicality over LAC, while providing high control performance and some flexibility of control gain assignment similar to HAC. The structure of a radiation cluster control system is outlined, showing that it is possible to control a target cluster without affecting the other clusters. A design procedure for the radiation cluster control system is then proposed. Numerical results are also presented.     

Monitoring radiation levels in the FEL accelerator hall

The radiation control system for the Free Electron Laser (FEL) monitors the radiation in its workplaces and accelerator hall. Gas-filled detectors installed in the accelerator hall are used for radiation monitoring and controlling beam losses in the vacuum chamber and for beam orbit correction.     

The influence of the orientation and strength of a magnetic field on the coherent population trapping in the Λ system

The influence of the orientation and strength of a magnetic field on the dynamics and dispersion of the populations of the multilevel Λ system upon spontaneous decay into thermostat levels is considered. The radiation field consists of two components and is specified by the vector-potential in the electric dipole approximation. From the solution of the Schödinger equation for a system consisting of an atom in a magnetic field + radiation field, the probability of populating a common level for the generalized Λ system is determined in the resonance approximation. The calculation of the dynamics and dispersion of the populations demonstrates their dependence on the orientation of the magnetic field vector with respect to the light field polarization vector and on the relationship between the magnetic field strength and radiation field intensities. The coherent population trapping occurs only in the case when Rabi frequencies either exceed or are comparable to the Zeeman splitting of magnetic sublevels. By varying the orientation of the magnetic field, it is possible to change the dynamics and dispersion of the populations, thus affecting the coherent population trapping.     

光子晶体对非晶纳米团簇辐射特性的影响

用有限时域差分法研究了非晶ZnO纳米团簇的辐射频谱,结果显示频谱呈自发辐射的特性. 为了对非晶纳米团簇的辐射输出进行有效的控制和利用,提出了利用光子晶体来控制纳米团簇的自发辐射,使之向所需要的频率内辐射的理论设计;并构想了一种制备简单、成本较低的实现方法,依据这种设想构建了一个二维系统,对其辐射特性进行数值模拟,结果显示光被有效地控制. 为制备可嵌入到集成光路中的、具有良好可加工性能的低阈值微型激光器提供了一条新途径. 关键词： 有限时域差分法 光子晶体 非晶纳米团簇 辐射特性     

The Effect of the Polarity and Design of the Discharge System on the X-ray Spectrum of the Micropinch Discharge Plasma

The spectral composition and X-ray radiation yield of a micropinch discharge plasma obtained at a facility of the low-inductance vacuum spark type are studied as a function of the polarity and design of the electrodes of the discharge system. It is shown that the X-ray radiation of the micropinch discharge plasma depends on the configuration of the electric field in the interval between the discharge electrodes, which determines the amount of erosion products involved in the micropinch process, resulting in the increase in the plasma density and its radiative characteristics.     

Nonlinear diffraction in a quantum-dot system with allowance for the Hubbard interaction

The propagation of monochromatic laser radiation in a volume system of quantum dots (QDs) that are tunnel-coupled along one axis is considered. The electron energy spectrum of the QD system is modeled in the tight-binding approximation with allowance for the Coulomb interaction of electrons in the Hubbard model. The electromagnetic field of laser radiation in a QD system is described quasi-classically by Maxwell equations; as applied to this problem, they are reduced to a non-one-dimensional wave equation for the vector potential. As a result of the analysis of the wave equation in the approximation of varying amplitudes and phases, an effective equation describing the electromagnetic field in a QD system is obtained and numerically solved. The influence of the parameters of the system and the amplitude and frequency of the field of incident laser radiation on the character of its propagation is investigated. Nonmonotonic dependences of the factor characterizing the laser beam diffraction spread on the parameters of the electron energy spectrum of the system are obtained.