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强太赫兹源是太赫兹科学技术发展的关键,其中大能量强场太赫兹脉冲源在超快物态调控、新型电子加速器等领域具有重要的应用前景.超快超强激光与等离子体相互作用是近年来发展起来的一种新型的强场太赫兹辐射产生途径.本文报道了利用超强飞秒激光脉冲与金属薄膜靶作用产生太赫兹辐射的实验结果,研究了激光能量和离焦量对靶后太赫兹辐射能量的影响,并通过监测激光背向散射光谱,定性揭示了其变化规律与不同光强下的电子加热机制的相关性.实验表征了太赫兹辐射的频谱、偏振及聚焦光斑情况.测量结果表明,实验产生了脉冲能量达458μJ、聚焦场强高达GV/m量级的超宽带太赫兹辐射,为开展极端太赫兹脉冲与物质相互作用研究提供了一种新的强场太赫兹光源. 相似文献
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Tani Masahiko Gu Ping Hyodo Masaharu Sakai Kiyomi Hidaka Takehiko 《Optical and Quantum Electronics》2000,32(4-5):503-520
We have reviewed and discussed the generation of continuous-wave terahertz radiation by the photomixing of dual-mode lasers, which includes a multi-mode laser diode (LD), a dual-mode microchip laser, a monolithic dual-mode DBR LD, and a widely tunable dual-mode external cavity LD. It is demonstrated by several experiments that the beat frequency of a dual-mode laser is more stable than the original laser modes because of the common-mode rejection effect. We also suggest a novel scheme by which the optical beat is stabilized to less than 1 kHz and its frequency can be precisely determined as well. 相似文献
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Abstract The European Synchrotron Radiation Facility (ESRF) is the first high-energy, high-brilliance synchrotron radiation source in operation today and it is ideally suited to high pressure research. White-beam and monochromatic diffraction techniques are being optimized in particular for structural studies of low-Z materials and poor scatterers generally, the best example being hydrogen single crystals at very high pressures. Most high pressure measurements are carried out on a versatile beamline equipped with a wiggler and an undulator. Focusing and image plates are used in all monochromatic angle-dispersive studies. The success of the high pressure programme has so far been achieved on a non-optimized beamline, but the next phase of the programme needs an optimized facility. A beamline is being constructed to fully exploit the intrinsic qualities of this unique source and insertion devices for high pressure studies. Its main design concepts are presented. 相似文献
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Focusing high-energy x-rays by a PMMA compound x-ray lens on Beijing synchrotron radiation facility 下载免费PDF全文
The x-ray compound lens is a novel refractive x-ray optical device.
This paper reports the authors' recent research on a polymethyl
methacrylate (PMMA) compound x-ray lens. Firstly the designing and
LIGA fabrication process for the PMMA compound x-ray lens are briefly
described. Then, a method for theoretical analysis, as well as the
experimental system for measurement is also introduced. Finally, the
focusing spots for 8keV monochromatic x-rays by the PMMA compound
x-ray lens are measured and analysed. According to the experimental
results, it is concluded that the PMMA compound x-ray lens promises a
good focusing performance under the high-energy x-rays. 相似文献
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We developed a continuous-spectrum light beam from Compton backscattering by using coherent synchrotron radiation in an L-band linac at the Kyoto University Research Reactor Institute. The ratio of Compton backscattered photons to background photons when coherent synchrotron radiation was used was three times larger than when coherent transition radiation was used. The transmission spectrum of a polystyrene film in the terahertz-wave region was evaluated by measuring the spectrum of the Compton backscattered photons and it roughly agreed with that measured by a Martin–Puplett-type interferometer. The spectrophotometry using Compton backscattering shows promise as a new tool for investigations in terahertz-wave science. 相似文献
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探测器是同步辐射实验的重要环节。探测器水平必须不断提高才能适应同步辐射发展的需求,最大限度地发挥先进光源为人类研究提供的强大支持作用。文章介绍了当前同步辐射实验中普遍使用的各种探测器的原理和特点,并就一些新型探测器的发展情况进行了阐述。 相似文献
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探测器是同步辐射实验的重要环节。探测器水平必须不断提高才能适应同步辐射发展的需求,最大限度地发挥先进光源为人类研究提供的强大支持作用。文章介绍了当前同步辐射实验中普遍使用的各种探测器的原理和特点,并就一些新型探测器的发展情况进行了阐述。 相似文献
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R. Kuroda N. Sei M. Yasumoto H. Toyokawa H. Ogawa M. Koike K. Yamada 《Infrared Physics & Technology》2008,51(5):390-393
The 0.1 THz coherent synchrotron radiation (CSR) was successfully generated in the 90° bending magnet of the compact S-band linac with the achromatic arc section using the ultra-short electron bunch which has the energy of 40 MeV, the bunch charge of about 1nc and the bunch length less than 1 ps (rms). The electron bunch compression of 1 nC electron bunch was achieved less than 1 ps (rms) by controlling the Q-magnets in the achromatic arc section as the bunch length was measured by the rms bunch length monitor. 相似文献
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Characteristics of terahertz coherent transition radiation generated from picosecond ultrashort electron bunches 下载免费PDF全文
This paper presents a method of generating terahertz (THz)
coherent transition radiation (CTR) from picosecond ultrashort
electron bunches including single and train bunches, which are
produced by a photocathode radio frequency gun. The radiation
characteristics of THz CTR including formation factor and energy
spectrum are analysed in detail. With the help of a 2-dimensional
particle-in-cell simulation, the radiation characteristics including
power, energy and magnetic field are analysed. The results show that
the radiation frequency can be adjusted by tuning the repetition
frequency of the train bunch and the energy can be enhanced with the
train bunches. 相似文献
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UV coherent radiation at 330.2 nm and IR stimulated radiations at 2.34μm,2.21μm and 1.64μm were generated via processes of unequal-frequency two-photon(3S-6S)resonantly enhanced excitation and equal frequency hybrid resonant excitation with particularexcited wavelength in Na_2-Na system.The competition of the two processes is obviously. 相似文献
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本文从偶极子辐射场的Heaviside-Feynman表达式出发, 用经典的电动力学方法推导了考虑内禀磁矩影响后的相对论电子辐射频谱分布的表达式, 并对做匀速圆周运动的极端相对论性电子的同步辐射, 计算了两个偏振方向上的考虑磁矩修正后的辐射谱. 计算结果表明对于特征频率为ωc的同步辐射, 如果ħωc≥10 keV, 内禀磁矩对辐射的修正是可观的. 通过同步辐射的内禀磁矩修正, 本文讨论了电子束极化度与辐射场偏振度的依赖关系, 并基于此关系提出一种测量电子束极化度的新方法.
关键词:
同步辐射
电子内禀磁矩
同步辐射偏振度
束流极化度 相似文献
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High brightness of SSRF brings about synchrotron radiation security problems, which will be solved in physics design. The main radiations are generated from bending magnets and insertion devices. Since the fact that radiation power and radiating area are different in these two kinds of synchrotron radiation, the arrangements of photon absorbers, diaphragms and other vacuum components need to be treated distinctively. In addition, SSRF interlock protection threshold is defined and the beam orbit in the straight line is limited. Hence, beam orbit in the bending magnets and IDs are also restricted by the threshold. The orbit restriction is calculated and helps us to arrange the vacuum components. In this paper, beam orbit distortion restricted by interlock protection threshold, radiation power, radiation angle and illuminating area are calculated. From the calculation results, the physics designs in manufacture and installation vacuum components are put forward. By commissioning, it is shown that physics requirements are met rigidly in the engineering process. 相似文献