Cooperative parametric (quasi-Cherenkov) radiation produced by electron bunches in natural or photonic crystals
Cooperative parametric (quasi-Cherenkov) radiation produced by electron bunches in natural or photonic crystals
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DOI：
10.1016/j.nimb.2015.03.054
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发表时间：
2015-07-15
影响因子：
1.3
通讯作者：
Baryshevsky, V. G.
中科院分区：
文献类型：
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作者：
Anishchenko, S. V.;Baryshevsky, V. G.
我们研究了在存在散粒噪声的电磁波动态衍射条件下，最初未调制的电子（正电子）束穿过晶体（天然或人造）时产生的协同参量（准切伦科夫）辐射的特征。对人造晶体中的协同太赫兹辐射进行了详细的数值分析。模拟中获得了超过200 MW/cm(2) 的辐射强度。研究了与粒子速度成小角度和大角度发射的协同辐射的峰值强度作为电子束电流密度的函数。峰值辐射强度似乎单调增加，直到达到饱和。在饱和状态下，散粒噪声会引起协同参量辐射强度的强烈波动。结果表明，辐射脉冲的持续时间可以比粒子穿过晶体的飞行时间长得多。这使得能够对现代加速器提供的电子束产生的协同参量辐射的时间结构进行彻底的实验研究。协同参量（准切伦科夫）辐射的复杂时间结构可以在所有光谱范围（X射线、光学、太赫兹和微波）的晶体（天然或人造）中观察到。 (C) 2015 Elsevier B.V. 保留所有权利。
We study the features of cooperative parametric (quasi-Cherenkov) radiation arising when initially unmodulated electron (positron) bunches pass through a crystal (natural or artificial) under the conditions of dynamical diffraction of electromagnetic waves in the presence of shot noise. A detailed numerical analysis is given for cooperative THz radiation in artificial crystals. The radiation intensity above 200 MW/cm(2) is obtained in simulations.The peak intensity of cooperative radiation emitted at small and large angles to particle velocity is investigated as a function of the current density of an electron bunch. The peak radiation intensity appeared to increase monotonically until saturation is achieved. At saturation, the shot noise causes strong fluctuations in the intensity of cooperative parametric radiation.It is shown that the duration of radiation pulses can be much longer than the particle flight time through the crystal. This enables a thorough experimental investigation of the time structure of cooperative parametric radiation generated by electron bunches available with modern accelerators.The complicated time structure of cooperative parametric (quasi-Cherenkov) radiation can be observed in crystals (natural or artificial) in all spectral ranges (X-ray, optical, terahertz, and microwave). (C) 2015 Elsevier B.V. All rights reserved.