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1.
由波荡器渡越辐射公式和电子通过wiggler边界产生的长波长辐射公式, 解析给出了电子通过光学速调管时产生的长波长辐射公式. 根据基本的电动力学公式数值计算出合肥同步辐射装置光学速调管的长波辐射, 并将其结果与解析公式的结果进行比较. 计算合肥同步辐射装置的光学速调管和弯转磁铁在红外波段范围内辐射的强度和通量, 表明光学速调管有很好的性能.本文说明, 光学速调管不但可以用来进行相干谐波的试验研究, 也可以兼用作储存环中的红外辐射光源.  相似文献   

2.
水中弹性圆柱壳的共振声辐射   总被引:5,自引:0,他引:5  
研究了在内壁简谐法向线力激励下的水中弹性圆柱壳的振动和声辐射问题,这有助于深入认识水中结构的声辐射机理,验证水下结构共振声辐射理论。本文从经典Rayleigh简正级数解出发导出共振声辐射公式,然后分别用经典公式和共振声辐射公式计算钢圆柱壳的辐射声功率及壳体表面声压曲线。计算结果表明两者符合良好。  相似文献   

3.
本文推导了极化电子被极化质子的深度非弹性散射的辐射修正公式, 其中包括了极化e-p散射的弹性尾巴的精确公式和非弹性散射辐射修正的峰值近似公式.  相似文献   

4.
黑体辐射中两类粒子的辐射规律   总被引:1,自引:1,他引:0  
孟庆苗 《大学物理》2005,24(8):9-10,18
考虑到相对论效应,采用量子统计的方法,得到了满足Bose-Einstein统计分布和Fermi-Dirac统计分布的两类粒子的黑体辐射公式(包括Planck黑体辐射公式).发现辐射谱不仅与黑体的辐射温度有关,还与辐射粒子的能量、化学势和种类有关.辐射强度与辐射粒子的能量、静质量、简并因子有关。  相似文献   

5.
空间辐射效应的蒙特-卡罗模拟   总被引:6,自引:0,他引:6       下载免费PDF全文
 概述了天然宇宙空间的辐射环境,简要地分析了辐射效应机制,在辐射效应的蒙特-卡罗模拟中对靶材料作了无定形假设,入射粒子在靶材料中的弹性能量损失采用经典二体散射公式,非弹性能量损失高能时采用Beth-Bloch公式,低能时采用Lindhard-Scharff公式,中能时采用插值公式,撞出晶格原子引起的次级损伤用Kinchin-Pease模型计算,最后对100KeV硼离子入射于硅材料引起的辐射效应进行了模拟计算,并给出了计算结果和分析。  相似文献   

6.
符五久  王安全 《大学物理》1999,18(7):8-10,12
把辐射看成是一群光子,从粒子的观点介绍了辐射压的概念,阐明了辐射压的物理实质,给出了计算辐射压的一般公式。  相似文献   

7.
普朗克黑体辐射定律的建立过程   总被引:1,自引:0,他引:1  
叙述了黑体辐射公式中几个重要结果维恩定律,瑞利-金斯公式和普朗克公式的建立过程,遵循普朗克的思路给出了普朗克公式的量子论解释。  相似文献   

8.
王惠明  刘家恩 《广西物理》2005,26(1):45-46,48
通过傅立叶变换给出运动电荷辐射的能量谱公式,进而导出非相对论性加速运动电荷的拉莫尔公式。  相似文献   

9.
水中弹性球壳的共振声辐射理论   总被引:4,自引:1,他引:3  
为了深入认识水中结构的声辐射机理,木文提出一个称为共振辐射理论(ResonanceRadiationTheory-RRT)的新理论。它是由共振散射理论(ResonanceScatterinyTheory-RST)推广得到的。对于一个在内壁简谐力激励下的水中弹性球壳,从经典的Rayleish简正级数解出发导出了共振辐射公式。水中薄钢球壳的辐射分波的数值计算表明,辐射形态函数与散射形态函数相似。由复共振极点参数按照共振辐射公式合成的辐射声功率曲线与严格理论的计算结果符合良好。  相似文献   

10.
把质能关系、质速关系、光子假说和跃迁辐射假说结合起来,导出了光频率变换公式,并且写出速度不很快的情况下自由粒子跃迁辐射的频率公式.最后对光子概念的实质作了简单介绍.  相似文献   

11.
基于图像的飞行器红外辐射特性测量   总被引:3,自引:0,他引:3  
曹西征  郭立红 《光学技术》2007,33(2):299-301,304
通过将目标在一定波段内的红外辐射等效为红外成像系统前一定距离下黑体在对应波段内的红外辐射,建立了等效辐射方程。根据黑体辐射定标实验数据,利用非线性回归方法确定了在不同的积分时间条件下红外凝视成像系统输出红外图像的灰度值与在一定距离下的黑体温度之间的定量关系,建立了辐射定标方程。在Visual C++6.0平台下,在对红外目标图像进行SUSAN滤波等预处理后,分析了已知目标距离的红外图像的灰度均值。首先根据辐射定标方程计算出目标等效为黑体的温度,然后利用等效辐射方程反推目标的红外辐射强度,以达到根据跟踪的红外图像确定红外目标辐射特性的目的。此项研究不仅可以为目标识别提供目标分类、识别和辨认所必需的光谱数据库,而且还可以为红外预警提供重要的参考数据。  相似文献   

12.
It is shown that a pre-existing dust ripple in a dusty plasma may excite tunable electromagnetic radiation. For our purposes, we use the Maxwell equation and the electron equation of motion to derive a Mathieu equation in the presence of a spatially oscillating dust ripple. The Mathieu equation admits instability of an electromagnetic wave. Criteria under which instability occurs are presented. Explicit expression for the electromagnetic radiation frequency and the growth rate are obtained. The possible relevance of our investigation to nonthermal electromagnetic radiation sources from laboratory and cosmic dusty plasmas is considered.  相似文献   

13.
It is shown that the one-dimensional problem of near-field microwave radiometry in the case of a smoothly inhomogeneous medium can be reduced to an integral equation similar to the well-known solution of the radiation transfer equation. The kernel of this integral equation depends on only one parameter determined experimentally. This makes it possible to determine the subsurface temperature profiles by using a set of near-field antennas of arbitrary design for which the sounding-depth range is overlapped by the effective depth of formation of the radiation received by these antennas. In the case of near-field measurements, the previously obtained joint solution of the radiation transfer equation and the thermal diffusion equation can also be modified and applied for monitoring the subsurface temperature profile using the temporal dependence of the received signal.  相似文献   

14.
The propagation of a quasimonochromatic wave packet of acoustic radiation in a discrete randomly-inhomogeneous medium under the condition that the carrier frequency of the packet is close to the resonance frequency of Mie scattering by an isolated scatterer is studied. The two-frequency Bethe-Salpeter equation in the form of an exact kinetic equation that takes account of the accumulation of the acoustic energy of the radiation inside the scatterers is taken as the initial equation. This kinetic equation is simplified by using the model of resonant point scatterers, the approximation of low scatterer density, and the Fraunhofer approximation in the theory of multiple scattering of waves. This leads to a new transport equation for nonstationary radiation with three Lorentzian delay kernels. In contrast to the well-known Sobolev radiative transfer equation with one Lorentzian delay kernel, the new transfer equation takes account of the accumulation of radiation energy inside the scatterers and is consistent with the Poynting theorem for nonstationary acoustic radiation. The transfer equation obtained with three Lorentzian delay kernels is used to study the Compton-Milne effect—trapping of a pulse of acoustic radiation diffusely reflected from a semi-infinite resonant randomly-inhomogeneous medium, when the pulse can spend most of its propagation time in the medium being “trapped” inside the scatterers. This specific albedo problem for the transfer equation obtained is solved by applying a generalized nonstationary invariance principle. As a result, the function describing the scattering of a diffusely reflected pulse can be expressed in terms of a generalized nonstationary Chandrasekhar H-function, satisfying a nonlinear integral equation. Simple analytical asymptotic expressions are found for the scattering function for the leading and trailing edges of a diffusely reflected δ-pulse as functions of time, the reflection angle, the mean scattering time of the radiation, the elementary delay time, and the parameter describing the accumulation of radiation energy inside the scatterers. These asymptotic expressions demonstrate quantitatively the retardation of the growth of the leading edge and the retardation of the decay of the trailing edge of a diffusely reflected δ-pulse when the conventional radiative transfer regime goes over to a regime of radiation trapping in a resonant randomly-inhomogeneous medium. Zh. éksp. Teor. Fiz. 113, 432–444 (February 1998)  相似文献   

15.
The equation describing the points of stationary phase for the integral representing the vector potential gives the conditions of existence and limits of regions of locally coherent radiation. The equation is applied to Cherenkov radiation and to the theory of conical spiral antennas.  相似文献   

16.
An envelope equation is derived which describes the radial evolution of a radiation beam propagating through a plasma. The radiation envelope equation contains a defocusing term due to diffraction spreading and a focusing term due to relativistic oscillations of the plasma electrons. The case of a constant density background plasma is analyzed in detail and an expression for a critical laser power is derived. For powers exceeding the critical power, the radiation envelope oscillates and does not diffract. Under certain conditions the radiation beam propagates through the plasma with a constant radius envelope.  相似文献   

17.
本文从辐时与传输的基本原理出发,引进辐射推动力及流热参数的概念,建立了一般情况下辐射传热的二阶微分方程的数学模型。该方程具有传输方程的特点,使得辐射传热的处理在方法上与导热、流动问题相一致。  相似文献   

18.
We discuss a simple method for solving the time-dependent transfer problem. This scheme is automatically flux-limited and affords physical insight into how flux limitation occurs. We then develop a second-order, time-dependent radiation energy equation that is similar in form to the diffusion limit radiation energy equation. This time-dependent energy equation approaches physically reasonable equations in optically thick and thin regions. Computational aspects of solving this energy equation are discussed.  相似文献   

19.
杨波 《物理学报》2008,57(2):1278-1284
在直线加速Kinnersley时空中,将相互耦合的Dirac方程化为二阶方程,采用新的乌龟坐标变换,在视界面附近消除二阶方程中的耦合化成了标准波动方程,得到辐射温度函数和Hawking热辐射谱. 关键词: 黑洞 Dirac方程 乌龟坐标变换 Hawking辐射  相似文献   

20.
杨波 《中国物理 B》2008,17(2):1278-1284
在直线加速Kinnersley时空中,将相互耦合的Dirac方程化为二阶方程,采用新的乌龟坐标变换,在视界面附近消除二阶方程中的耦合化成了标准波动方程,得到辐射温度函数和Hawking热辐射谱.  相似文献   

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