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We investigate the effects of a weak gravitational wave, modelled as a gaussian wavepacket, on the polarization state of an
electromagnetic field enclosed in a cavity. Our approach is semiclassical, in that the electromagnetic field is described as a quantum field, while the gravitational perturbation is treated classically,
as a slightly curved background spacetime. Assuming that before the interaction the electromagnetic field has been prepared
in a given polarization state, we show that – due to the gravitational scattering with the wave – some photons having different
polarization states are found in the cavity at late times. Such polarization scattering has some resemblance with Thomson
scattering, well-known in Quantum Electrodynamics: hence the motivation for the title. We give a numerical estimate of the
resulting photon polarization spreading in the case of a typical gravitational burst from a final supernova rebound. We also
briefly comment about the possible influence of such gravitational scattering on the Cosmic Microwave Background (CMB) polarization. 相似文献
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随着激光和加速器技术的发展,激光场强度和粒子能量也有所提升,在高场强和高电子能量的条件下,电子与光子的汤姆孙散射过程将达到高度非线性状态,在这种状态下会发生多光子效应,即单个电子同时与多个光子相互作用并辐射一个高能光子,此过程通常称为多光子汤姆孙散射.当场强和粒子能量变得更高时,需要引入量子电动力学理论来解决极端光场物理中的动理学过程.近期,全球多台数拍瓦激光装置逐渐投入使用,激光等离子体相互作用中的此类效应会变得极其显著.而全光汤姆孙散射成为目前研究极端光场物理最佳的实验方案,因此,系统地研究全光多光子汤姆孙散射是本领域未来十年极其重要的方向.本文对近年来全光汤姆孙散射实验从单光子、低阶多光子到高阶多光子的研究进展进行了综述,并对其未来的发展方向进行了展望.另外,伴随着散射过程产生的准直高亮X/伽马射线,有望发展成为具有重要应用价值的紧凑型超亮高能光源. 相似文献
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研究了超短激光脉冲驱动的Thomson散射的辐射空间分布. 发现辐射的空间分布对称性显著地依赖于超短脉冲的载波相位η0,在η0=0,π时,辐射的空间分布呈现出二重或一重对称性;而在其他载波相位时,这些空间分布对称性遭到破坏. 辐射光的准直性也依赖于驱动脉冲的载波相位,在η0=±π/2时辐射光的准直性最好. 这些结果表明可以通过改变驱动激光脉冲的载波相位来控制辐射光的空间分布,也可以利用辐射空间分布对相位的依赖特性来测量超短激光脉冲的载波相位.
关键词:
Thomson散射
空间分布
载波相位 相似文献
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用经典辐射理论对线偏振周期量级激光脉冲的线性Thomson散射进行分析,从理论上得到它可产生亚阿秒脉冲的结论. 计算显示,在电子相对论因子为50、激光脉冲中心波长为1μm、归一化光场强度为0.01的情况下,用包含1.5个光周期的激光脉冲,可获得0.2as(半高全宽)的散射脉冲输出. 还对光场载波包络初相φce和电子进入光场的初相φin对散射脉冲的影响作了分析讨论,结果表明,在适当的φce和φin条件下,能实现单个阿秒脉冲输出,并可对脉冲宽度和频率进行调谐.
关键词:
线性Thomson散射
周期量级激光脉冲
载波包络初相
阿秒脉冲 相似文献
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We develop the theory for light scattering as a diagnostic method for plasmas in nonequilibrium states. We show how well-known nonequilibrium features, like beam acoustic modes, arise in the spectra. The analysis of an experiment with strongly driven electrons demonstrates the abilities of the new approach; we find qualitatively different scattering spectra for different times and excellent agreement with the experimental data after time integration. Finally, an analysis of data from dense beryllium suggests that an energetic electron component exists in this experiment as well. 相似文献
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Juurinen I Nakahara K Ando N Nishiumi T Seta H Yoshida N Morinaga T Itou M Ninomiya T Sakurai Y Salonen E Nordlund K Hämäläinen K Hakala M 《Physical review letters》2011,107(19):197401
Water-ethanol mixtures exhibit interesting anomalies in their macroscopic properties. Despite a lot of research, the origin of the anomalies and the microscopic structure itself is still far from completely known. We have utilized the synchrotron x-ray Compton scattering technique to elucidate the structure of aqueous ethanol from a new experimental perspective. The technique is uniquely sensitive to the local molecular geometries at the angstrom and subangstrom scales. The experiments reveal two distinct mixing regimes in terms of geometry: the dilute 5 mol % and the concentrated >15 mol % regimes. By comparing with pure liquids, the former regime is characterized by an intramolecular and the latter by an intermolecular change. The findings bring new light to evaluating the hypothesis of formation of clathratelike structures at the dilute concentrations. 相似文献
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W. Schülke 《Solid State Communications》1982,43(11):863-866
Off-diagonal elements ?-1 (q, q + gh, ω) of the inverse dielectric matrix are shown to be measurable by means of inelastic scattering of X-ray photons from two different modes of the wave field, which is generated within the analyzer of a Laue-case X-ray interferometer at the interference position. 相似文献
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Froula DH Davis P Divol L Ross JS Meezan N Price D Glenzer SH Rousseaux C 《Physical review letters》2005,95(19):195005
The dispersion of ion-acoustic fluctuations has been measured using a novel technique that employs multiple color Thomson-scattering diagnostics to measure the frequency spectrum for two separate thermal ion-acoustic fluctuations with significantly different wave vectors. The plasma fluctuations are shown to become dispersive with increasing electron temperature. We demonstrate that this technique allows a time resolved local measurement of electron density and temperature in inertial confinement fusion plasmas. 相似文献
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S. Yu. Tolstyakov V. K. Gusev M. M. Kochergin G. S. Kurskiev E. E. Mukhin Yu. V. Petrov G. T. Razdobarin V. V. Semenov Yu. E. Kamach E. N. Kozlovskiĭ Yu. B. Pirozhkov L. L. Shapiro 《Technical Physics》2006,51(7):846-852
Specific features of the Thomson scattering diagnostics, its main characteristics and capabilities, and the results of its experimental testing in the Globus-M tokamak are described. A powerful multipulse neodymium-glass laser is designed for investigating both fast and slow processes in the tokamak plasma. The laser is capable of generating up to 20 pulses uniformly distributed in time during one tokamak discharge. In order to investigate fast transient processes, the laser repetition rate can be increased within a specified time interval. The possibility of varying the time interval between laser pulses from 0.5 ms to 1.0 s makes this diagnostics highly informative. The optical scheme developed in the course of these studies allowed one to simplify the power supply system and create a comparatively inexpensive laser system. The use of avalanche photodiodes and filtering polychromators with a high optical transparency provides high sensitivity of the diagnostics. A special software was designed that allows automatic processing of several hundred signals during one shot and provides data on the electron density and temperature immediately in the course of measurements. The diagnostics allows one to trace the time behavior of the spatial profiles of the electron temperature and density in both ohmic discharges and discharges with auxiliary heating, as well as in experiments with particle injection with a plasma gun. 相似文献
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在神光III原型装置上,利用8束三倍频(351.0 nm)激光注入充气黑腔产生大尺度高温等离子体并激发高水平受激布里渊散射(SBS)过程。利用1束四倍频(263.3 nm)探针束和1套广角汤姆逊散射诊断系统,获得了三倍频激光SBS过程驱动的离子声波的超热相干汤姆逊散射(STS)光谱。通过对STS光谱和背向SBS光谱进行联合分析,揭示了SBS的时空演化过程。 相似文献