共查询到20条相似文献,搜索用时 46 毫秒
1.
P. V. Vagin U. Englisch T. Müller A. Schöps M. Tischer 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2011,5(6):1055-1057
PETRA III is a new hard X-ray synchrotron radiation source, operating at 6 GeV with a beam current of up to 100 mA and extremely
low horizontal emittance of 1 nm rad. Such low emittance is achieved by using two 100 m long damping wiggler sections which
reduce the emittance by a factor of 4. Altogether the damping sections contain 20 wigglers of 4m length each. The emitted
synchrotron radiation power produced by wigglers amounts to 420 kW at 100 mA beam current in total. In the new octant of PETRA
III, there are 14 undulator beamlines, with a brilliance up to 1021 (s mrad2 mm2 0.1% BW)−1 which cover an energy range from 0.3 keV to more than 100 keV. The low emittance raises very high requirements to the field
quality of the insertion devices. At first, it should not affect the positron beam trajectory. Secondly, the spectral properties
of the radiation created, like the intensity of higher harmonics, should not be limited by the undulator field quality, but
by the beam emittance effects in order to have some reserve for future machine upgrades or possible radiation demagnetization.
This paper presents the current status of PETRA III insertion devices and describes intermediate commissioning results like
impact of IDs on the positron beam orbit or photon beam and radiation problems. 相似文献
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A. Hofmann 《Physics Reports》1980,64(5):253-281
The properties of synchrotron radiation from LEP are investigated. This radiation from LEP are investigated. This radiation is assumed to be in a parasitic mode without changing any of the operating parameters. At 86 GeV the radiation from the normal bending magnet has a critical energy of 0.4 MeV and a power of ~500 W/m, and is probably of limited interest. High photon energies (10–20 MeV) of high intensity can be obtained from normal and superconducting wiggler magnets. Undulators can give quasi-monochromatic radiation of high brightness with photon energies of up to 5 MeV. New magnet developments might increase this energy range. Quasi-monochromatic γ-rays of ~100 MeV can be created with soft Compton back scattering without disturbing the electron bean. This relies on future free electron lasers in the submillimetre range. The natural collimation, the polarization and the time structure make all these photon beams unique tools for research in nuclear physics. The synchrotron rediation can be used to produced photoneutrons with intensities of up to 1014 neutrons/s. It is foreseen that LEP will be equipped with superconducting cavities in later stage and that is energy will be increased to ~130 GeV. This will approximately double the photon energies obtained from wigglers and undulators. 相似文献
4.
用理论和数值的方法, 首次研究了扭摆器中相干同步辐射效应诱发的微束团不稳定性. 这一不稳定性只存在于小能散的情况, 并当电子能量或峰值磁场取特定值时, 不稳定度达到最大值. 在BFEL的扭摆器中, 可能有轻微的不稳定性存在; 在CTF的扭摆器中, 则不会有不稳定性发生. 相似文献
5.
Herman Winick 《Synchrotron Radiation News》2015,28(4):26-27
I am indebted to Karl Brown for suggesting that I invite Klaus, who I did not know at the time, to a workshop on wiggler magnets in March 1977. I recall Karl saying to me something like, “Herman, if you want someone who knows about magnets, you should invite Klaus Halbach.” Klaus came and even made a contribution about some aspects of the design of electromagnet wigglers, the only type of wigglers that had been considered to that time. However, it was at that workshop that Klaus got his introduction to synchrotron radiation, mostly by listening to talks by Albert Hofmann and Andy Sesler, who explained the marvelous properties of undulator magnets as radiation sources. Klaus filed this information in his long-term memory banks while working on other topics, particularly the design of permanent magnet quadrupoles for proton linacs. 相似文献
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Yoshiaki Tsunawaki Nobuhisa Ohigashi Kunioki Mima Shin-ichiro Kurama Kazuo Imasaki Masayuki Fujita Chiyoe Yamanaka Sadao Nakai 《International Journal of Infrared and Millimeter Waves》1995,16(1):317-325
A three dimensional simulation software system developed to estimate a free electron laser (FEL) gain has been applied to FEL using a standard plane polarized wiggler and an alternately shifted magnet wiggler. It is seen for the latter wiggler that a large filling factor could be selected and each maximum gain corresponding to each orbit of electron beam concentrates at a certain frequency region of FEL radiation. It is, therefore, implied that a proper shift between the adjacent magnets in the wiggler produces the improvement of the FEL gain. 相似文献
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Single‐crystal diamond is a material with great potential for the fabrication of X‐ray photon beam‐position monitors with submicrometre spatial resolution. Low X‐ray absorption combined with radiation hardness and excellent thermal‐mechanical properties make possible beam‐transmissive diamond devices for monitoring synchrotron and free‐electron laser X‐ray beams. Tests were made using a white bending‐magnet synchrotron X‐ray beam at DESY to investigate the performance of a position‐sensitive diamond device using radiofrequency readout electronics. The device uniformity and position response were measured in a 25 µm collimated X‐ray beam with an I‐Tech Libera `Brilliance' system. This readout system was designed for position measurement and feedback control of the electron beam in the synchrotron storage ring, but, as shown here, it can also be used for accurate position readout of a quadrant‐electrode single‐crystal diamond sensor. The centre‐of‐gravity position of the F4 X‐ray beam at the DORIS III synchrotron was measured with the diamond signal output digitally sampled at a rate of 130 Msample s?1 by the Brilliance system. Narrow‐band filtering and digital averaging of the position signals resulted in a measured position noise below 50 nm (r.m.s.) for a 10 Hz bandwidth. 相似文献
11.
Boscolo I. Giuliani F. Valentini M. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(3):256-262
A powerful, continuous-wave millimeter radiation source is presented. An electrostatic Cockcroft-Walton accelerator (2.5 MV) drives an FEL (free-electron laser) of 1 MW power. The accelerator has a new design in order to obtain a very powerful (50 MW) electron beam and very small ripple. A recovery system is used to increase RF power and efficiency. The FEL oscillator is 1.5-m long, with a permanent magnet helical wiggler. The cavity is equipped with Bragg mirrors. The FEL is set at the high voltage terminal 相似文献
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在FEL实验中,电子束通过摇摆器,一方面由于周期性磁场作用,电子束轨迹要周期性的摆动,另一方面还要辐射同FEL辐射波长一致的自发辐射,该辐射谱反映电子束、摇摆器集成后的参数。在CAEP(Institute of China Academic Engineering Physics)远红外100 μm FEL实验中,自发辐射谱通过Ge∶Ga低温探头和远红外100 μm光栅谱仪测量。文章侧重从实际摇摆器磁场分析了远红外100 μm FEL的自发辐射谱。 相似文献
13.
Botton M. Ron A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1990,18(3):416-423
The analysis of the interaction between electromagnetic waves and electron beams in semi-infinite wigglers is presented. The beam is assumed to include two cold streams of electrons; hence, its space-charge waves may be unstable (two-stream instability). In the wiggler, this instability is shown to yield much larger growth rates (up to seven times greater) than in the conventional one-stream free electron laser (FEL). Accordingly, the gain per pass is enhanced by orders of magnitude. The enhancement of the two-stream instability is shown to be most effective for short-period wigglers 相似文献
14.
毫米波自由电子激光的数值模拟和实验的比较 总被引:2,自引:0,他引:2
从波导管毫米波自由电子激光器的设计要求出发,根据Livermore实验室FRED程序的物理思想,编制了空间三维的数值模拟程序(WAGFEL)。为了检验程序的可靠程度,结合ELF装置的实际参数,进行了数值模拟并和实验结果进行了比较。结果表明,把Wiggler磁场B_w增大300 Gs后,WAGFEL程序的模拟结果和Livermore实验室的实验结果基本符合。模拟使用的全部参数,除B_w增大300Gs外,都是ELF的实际参数。模拟时峰值磁场B_w=4050Gs,实验测量峰值磁场B_w=3720Gs,相差在8%左右。WAGFEL程序可以用来从事毫米波自由电子激光器的设计以及基本物理问题的研究。 相似文献
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For the calibration of radiometric transfer standards by means of electron synchrotron radiation an apparatus has been developed which is in service at DESY, Hamburg. The equipment is used to calibrate commercial deuterium lamps (165 nm to 340 nm). The uncertainty of the “absolute” spectral radiance is ± 4%, whereas that of the relative spectral radiance is ± 2%. 相似文献
16.
Yoshiaki Tsunawaki Mie Noguchi Mitsuhiro Kusaba Nobuhisa Ohigashi Masayuki Fujita Kazuo Imasaki Shin-ichiro Kuruma Kunioki Mima Sadao Nakai Chiyoe Yamanaka 《International Journal of Infrared and Millimeter Waves》1998,19(2):177-184
A hybrid planar wiggler with a period of 20 mm has been studied as the simplest one which gives the strong field including some higher harmonic components by selecting proper sizes of the ferromagnetic and the permanent magnet. Small gap length of the wiggler and small width of permendur satisfy these conditions to a certain degree.Gain analysis of FEL suggests that for high wiggler field of K>1 1.6, higher harmonic gains are improved primarily due to its strong field, and for low wiggler field of K< 1 1.6, they are mainly due to the modification of the wiggler field distribution. 相似文献
17.
Jiawwen CHEN Zhijiang WANG-Shanghai Institute of Optics Fine Mechanics Academia Sinica P. O. Box - Shanghai China 《Chinese Journal of Lasers》1992,1(1):9-15
In this paper a method for realizing the short-wavelength-radiation issupposed,with the wiggler ampiltude to be made the periodic gradient function of theaxial coordinate Z so that the wiggler could be regarded as the superimposing of variouswigglers and one of which could be selected to amplify the radiation field with givenwavelength.Finally,the gain expression as well as the energy transfer rate for suchdevice is given. 相似文献
18.
Periodic magnetic structures (wigglers) have been successfully used for a long time for controlling beam parameters in charged-particle storage rings for various purposes (including the reduction of emittance). In this work, we optimize the optical functions of the storage ring gap into which a wiggler is installed for a more effective reduction of the emittance. Optimal solutions are obtained for the first time for FODOtype and theoretical minimum emittance (TME) structures. An original method is proposed for suppressing the contribution of the wiggler fields to the radiation excitation of the phase volume of the beam by modulating the field period along the wiggler axis. 相似文献
19.
Campbell L.P. Dilley C.E. Gottschalk S.C. Kimura W.D. Quimby D.C. Steinhauer L.C. Babzien M. Ben-Zvi I. Gallardo J.C. Kusche K.P. Jr. Pogorelsky I.V. Skaritka J.R. Van Steenbergen A. Yakimenko V.E. Cline D.B. Ping He Yabo Liu Pantell R.H. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2000,28(4):1143-1151
The goal of the staged electron laser acceleration (STELLA) experiment is to demonstrate staging of the laser acceleration process whereby an inverse free electron laser (IFEL) will be used to prebunch the electrons, which are then accelerated in an inverse Cerenkov accelerator (ICA). As preparation for this experiment, a new permanent magnet wiggler for the IFEL was constructed and the ICA system was modified. Both systems have been tested on a new beamline specifically built for STELLA. The improved electron beam (e-beam) with its very low emittance (0.8 mm-mrad normalized) enabled focusing the e-beam to an average radius (1σ) of 65 μm, within the ICA interaction region. This small e-beam focus greatly enhanced the ICA process and resulted in electron energy spectra that have demonstrated the best agreement to date in both overall shape and magnitude with the model predictions. The electron energy spectrum using the new wiggler in the IFEL was also measured. These results will be described as well as future improvements to the STELLA experiment 相似文献
20.
R. W. Schoenlein A. H. Chin H. H. W. Chong R. W. Falcone T. E. Glover P. A. Heimann 《Synchrotron Radiation News》2013,26(1):20-27
On May 19, 2004, 250 guests from all over the world joined the DESY research center to celebrate 40 years of research with synchrotron radiation at DESY in Hamburg. “The first measurements with the light beam from the DESY ring accelerator started in 1964. DESY was one of the seed laboratories in which the worldwide success story of research with synchrotron radiation began,” Albrecht Wagner, chairman of the DESY Board of Directors, explained in his welcoming address. “Today, more than 1,900 scientists from 31 countries come to DESY every year to carry out experiments with synchrotron radiation.” Forty years ago, synchrotron radiation at DESY started from scratch. At the beginning of the 1960s, the radiation generated by the electrons in the bending magnets of their new 6 GeV electron synchrotron was regarded by DESY particle physicists as an unwanted, disruptive effect. 相似文献