共查询到20条相似文献,搜索用时 312 毫秒
1.
Takayama Y Kamada S 《Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics》1999,59(6):7128-7140
In this paper we discuss how the first-order spatial coherence of bending magnet radiation is determined. We present an analytical representation of the coherence and compare it with the numerical calculations based on the first principles. It is shown that if the electron-beam size is so large that some conditions are satisfied, the van Cittert-Zernike theorem can be used without any modification in the vertical and horizontal directions. The formalism presented will be useful in judging whether or not the electron-beam size in the storage ring can be estimated directly from the van Cittert-Zernike theorem using the synchrotron radiation interferometer. 相似文献
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Sannibale F Byrd JM Loftsdóttir A Venturini M Abo-Bakr M Feikes J Holldack K Kuske P Wüstefeld G Hübers HW Warnock R 《Physical review letters》2004,93(9):094801
We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSY II storage ring. We also use this model to optimize the performance of a source for stable CSR emission. 相似文献
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The conceptual of Hefei Advanced Light Source, which is an advanced VUV and Soft X-ray source, was developed at NSRL of USTC. According to the synchrotron radiation user requirements and the trends of SR source development, some accelerator-based schemes were considered and compared; furthermore storage ring with ultra low emittance was adopted as the baseline scheme of HALS. To achieve ultra low emittance, some focusing structures were studied and optimized in the lattice design. Compromising of emittance, onmomentum and off-momentum dynamic aperture and ring scale, five bend acromat (FBA) was employed. In the preliminary design of HALS, the emittance was reduced to sub nm·rad, thus the radiation up to water window has full lateral coherence. The brilliance of undulator radiation covering several eVs to keVs range is higher than that of HLS by several orders. The HALS should be one of the most advanced synchrotron radiation light sources in the world. 相似文献
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P. Skopintsev A. Singer J. Bach L. Müller B. Beyersdorff S. Schleitzer O. Gorobtsov A. Shabalin R. P. Kurta D. Dzhigaev O. M. Yefanov L. Glaser A. Sakdinawat G. Grübel R. Frömter H. P. Oepen J. Viefhaus I. A. Vartanyants 《Journal of synchrotron radiation》2014,21(4):722-728
A method to characterize the spatial coherence of soft X‐ray radiation from a single diffraction pattern is presented. The technique is based on scattering from non‐redundant arrays (NRAs) of slits and records the degree of spatial coherence at several relative separations from 1 to 15 µm, simultaneously. Using NRAs the spatial coherence of the X‐ray beam at the XUV X‐ray beamline P04 of the PETRA III synchrotron storage ring was measured as a function of different beam parameters. To verify the results obtained with the NRAs, additional Young's double‐pinhole experiments were conducted and showed good agreement. 相似文献
5.
Harel Primack Reinhold Blümel 《The European Physical Journal A - Hadrons and Nuclei》1998,3(4):299-301
With respect to a “hot”, non-crystallized beam the synchrotron radiation of a cold crystallized beam is considerably modified.
We predict suppression of synchrotron radiation emitted by a crystallized beam in a storage ring. We also propose experiments
to detect this effect.
Received: 19 June 1998 / Revised version: 10 August 1998 相似文献
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Fernando Sannibale Augusto Marcelli Plinio Innocenzi 《Journal of synchrotron radiation》2008,15(6):655-659
IKNO (Innovation and KNOwledge) is a proposal for a multi‐user facility based on an electron storage ring optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range, and of broadband incoherent synchrotron radiation ranging from the IR to the VUV. IKNO can be operated in an ultra‐stable CSR mode with photon flux in the terahertz frequency region up to nine orders of magnitude higher than in existing third‐generation light sources. Simultaneously to the CSR operation, broadband incoherent synchrotron radiation up to VUV frequencies is available at the beamline ports. The main characteristics of the IKNO storage and its performance in terms of CSR and incoherent synchrotron radiation are described in this paper. The proposed location for the infrastructure facility is Sardinia, Italy. 相似文献
8.
We report on the first energy-resolved (retarding field mode) spin polarized photoemission measurement from a Ni(111) single crystal using synchrotron radiation from the ACO storage ring at LURE(ORSAY) It is shown that exchange effects can be detected for electron states well below the Fermi energy and that spin polarized, constant-initial-state spectroscopy of ferromagnets using synchrotron radiation is feasible. 相似文献
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Lars Lindqvist Ricardo Lopez-Delgado Monique M. Martin André Tramer 《Optics Communications》1974,10(3):283-287
For the first time storage ring synchrotron radiation has been used as a repetitive source for time spectroscopy. Very fast fluorescence decays (shorter than 1 nsec) have been measured with an accuracy of the order of 10%, by the Single Photon Counting technique. Also fast protolytic reactions occuring in the excited state of 2-naphthol and fluorescein have been investigated by the Delayed Coincidence technique (time-resolved fluorescence). Storage ring synchrotron radiation characteristics are compared with those of the nanosecond flash lamps, conventionally used for this kind of measurements. 相似文献
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同步辐射光源是带电粒子在加速器储存环中以接近光速的速度运动时,沿轨道切线方向发射出的辐射,同步辐射X射线荧光分析(SR-XRF)是以同步辐射X射线作为激发光源的X荧光光谱分析技术.同步辐射X射线荧光分析包括了用于微区及微量元素分析的同步辐射XRF、用于表面及薄膜分析的同步辐射全反射X射线荧光(SR-TXRF)以及用于三... 相似文献
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在科学技术新需求的推动下,同步辐射光源持续往前发展。目前,同步辐射装置发展已历经三代,正处于第四代同步辐射光源蓬勃发展阶段。基于衍射极限储存环的同步辐射装置是第四代同步辐射光源的典型代表之一。第四代同步辐射光源主要发展趋势是进一步减小电子束流发射度,使光源具有极好的横向相干性,以及产生圆截面辐射的能力。如果束流发射度降至光学衍射极限“辐射波长/4π”,其亮度比第三代同步辐射光源高2个数量级。这种同步辐射光源在性能上发生的质的飞跃,将给同步辐射实验技术带来实质性的突破,从而给前沿科学技术研究和现代产业发展带来全新的机遇。从国际同步辐射发展趋势入手,首先介绍低能区衍射限储存环光源的特色和性能,然后介绍其带来的同步辐射实验技术的进步,并浅析低能区衍射限储存环光源在材料科学、能源科学、生命科学和环境科学上的应用,以及其带来的产业机遇。最后,总结和展望了低能区衍射限储存环光源带来的技术突破和潜在的应用前景。 相似文献
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Wang F Cheever D Farkhondeh M Franklin W Ihloff E van der Laan J McAllister B Milner R Tschalaer C Wang D Wang DF Zolfaghari A Zwart T Carr GL Podobedov B Sannibale F 《Physical review letters》2006,96(6):064801
The generation of brilliant, stable, and broadband coherent synchrotron radiation (CSR) in electron storage rings depends strongly on ring rf system properties such as frequency and gap voltage. We have observed intense coherent radiation at frequencies approaching the THz regime produced by the MIT-Bates South Hall Ring, which employs a high-frequency S-band rf system. The measured CSR spectral intensity enhancement with 2 mA stored current was up to 10,000 times above background for wave numbers near 3 cm(-1). The measurements also uncovered strong beam instabilities that must be suppressed if such a very high rf frequency electron storage ring is to become a viable coherent THz source. 相似文献
14.
Harry Westfahl Jr Sérgio A. Lordano Luiz Bernd C. Meyer Florian Meneau 《Journal of synchrotron radiation》2017,24(3):566-575
In this work the coherence properties of the synchrotron radiation beam from an X‐ray undulator in a fourth‐generation storage ring are analyzed. A slightly focused X‐ray beam is simulated using a wavefront propagation through a non‐redundant array of slits and the mutual coherence function is directly obtained and compared with the Gaussian–Schell approximation. The numerical wave propagation and the approximate analytical approaches are shown to agree qualitatively, and it is also shown that, when the coherent fraction is selected by a finite aperture before the focusing element, even achromatic focusing systems like total reflection mirrors become slightly chromatic. This effect is also well accounted for in the Gaussian–Schell model. The wavefront propagation simulation through the non‐redundant array was repeated with an imperfect mirror demonstrating that, although the wavefront is distorted, its coherent length is practically unchanged. 相似文献
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In this paper we describe the properties of the SPEAR storage ring at the Stanford Linear Accelerator Center as a synchrotron radiation source for X-ra 相似文献
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《中国物理C(英文版)》2015,(7)
Indus-2 is an Indian synchrotron light source, operating at 2.5 Ge V and generating synchrotron radiation from its bending magnets. In order to provide more intense synchrotron radiation to the synchrotron users, there is a plan to install five insertion devices in the Indus-2 storage ring. In the first phase of installation of insertion devices, there is a proposal to install two out- vacuum pure permanent magnet linearly polarized undulators in long straight sections of the Indus-2 storage ring. The presence of the insertion devices in the ring has inevitable effects on beam parameters like betatron tune, betatron amplitude function, closed orbit, emittance, energy spread and dynamic aperture etc. In this paper, the effect of two undulators on the above mentioned parameters of the Indus-2stored electron beam at 2.5 Ge V is presented. Moreover a correction scheme for the restoration of the betatron tune and amplitude function is also presented. 相似文献
18.
J. M. Byrd Michael C. Martin W. R. McKinney D. V. Munson H. Nishimura D. S. Robin F. Sannibale R. D. Schlueter W. G. Thur J. Y. Jung W. Wan 《Infrared Physics & Technology》2004,45(5-6):325-330
We present the concepts for an electron storage ring dedicated to and optimized for the production of stable coherent synchrotron radiation (CSR) over the far-infrared terahertz wavelength range from 200 μm to about 1 cm. CIRCE (Coherent InfraRed CEnter) will be a 66 m circumference ring located on top of the ALS booster synchrotron shielding tunnel and using the existing ALS injector. This location provides enough floor space for both the CIRCE ring, its required shielding, and numerous beamlines. We briefly outline a model for CSR emission in which a static bunch distortion induced by the synchrotron radiation field is used to significantly extend the stable CSR emission towards higher frequencies. This model has been verified with experimental CSR results. We present the calculated CIRCE photon flux where a gain of 6–9 orders of magnitude is shown compared to existing far-IR sources. Additionally, the particular design of the dipole vacuum chamber has been optimized to allow an excellent transmission of these far-infrared wavelengths. We believe that the CIRCE source can be constructed for a modest cost. 相似文献
19.
研究了逆流相对论高能电子与强激光脉冲相互作用的同步辐射过程,当电子具有合适的初速度且传播方向与激光的传播方向相反时,电子在激光脉冲中心作圆周运动。由于电子的运动半径比传统同步辐射环中电子的运动半径小几个数量级,因此电子的辐射能量大大增加。研究发现此过程可以获得阿秒和泽秒X射线脉冲;同时发现随着入射电子初能量的增加和激光能量的增强,获得X射线脉冲脉宽越来越短,强度越来越大。这使得激光同步辐射可以成为一种强大的短波长短脉宽的辐射光源。 相似文献