共查询到20条相似文献,搜索用时 93 毫秒
1.
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
2.
《中国物理C(英文版)》2015,(7)
This paper theoretically proves that an electron storage ring can generate coherent radiation in the THz region using a quick kicker magnet and an AC sextupole magnet. When the vertical chromaticity is modulated by the AC sextupole magnet, the vertical beam collective motion excited by the kicker produces a wavy spatial structure after a number of longitudinal oscillation periods. The radiation spectral distribution was calculated from the wavy bunch parameters at the Hefei Light Source(HLS). When the electron energy is reduced to 400 Me V, extremely strong coherent synchrotron radiation(CSR) at 0.115 THz should be produced. 相似文献
3.
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
4.
You Yan Yan LiXin Du YingChao Hua JianFei Huang WenHui Tang ChuanXiang 《中国科学:物理学 力学 天文学(英文版)》2011,54(2):197-200
Tunable and compact high power terahertz (THz) radiation based on coherent radiation (CR) of the picosecond relativistic electron bunch train is under development at the Tsinghua accelerator lab. Coherent synchronization radiation (CSR) and coherent transition radiation (CTR) are researched based on an S-band compact electron linac, a bending magnet or a thin foil. The bunch train’s form factors, which are the key factor of THz radiation, are analyzed by the PARMELA simulation. The effects of electron bunch trains under different conditions, such as the bunch number, bunch charges, micro-pulses inter-distance, and accelerating gradient of the gun are investigated separately in this paper. The optimal radiated THz power and spectra should take these factors as a whole into account. 相似文献
5.
Narrow-band THz coherent Cherenkov radiation can be driven by a subpicosecond electron bunch trav- eling along the axis of a hollow cylindrical dielectric-lined waveguide. We present a scheme of compact THz radiation source based on the photocathode rf gun. On the basis of our analytic result, the subpicosecond electron bunch with high charge (800 pC) can be generated directly in the photocathode rf gun. According to the analytical and simulated results, a narrow emission spectrum peaked at 0.24 THz with 2 megawatt (MW) peak power is expected to gain in the proposed scheme (the length of the facility is about 1.2 m). 相似文献
6.
Narrow-band THz coherent Cherenkov radiation can be driven by a subpicosecond electron bunch traveling along the axis of a hollow cylindrical dielectric-lined waveguide. We present a scheme of compact THz radiation source based on the photocathode rf gun. On the basis of our analytic result, the subpicosecond electron bunch with high charge (800 pC) can be generated directly in the photocathode rf gun. According to the analytical and simulated results, a narrow emission spectrum peaked at 0.24 THz with 2 megawatt (MW) peak power is expected to gain in the proposed scheme (the length of the facility is about 1.2 m). 相似文献
7.
The time structure of a burst of coherent synchrotron radiation (CSR) emitted from a high-peak-current beam in the electron storage ring NewSUBARU has been investigated. The source of this CSR burst is fine time structure in a bunch produced by longitudinal beam instability. This burst is unstable but very easy to obtain, so it can be used for some experimental applications with appropriate averaging of data. With an averaging period of 10 ms, the fluctuation of the integrated power was about 10%. 相似文献
8.
The experimental result of terahertz (THz) coherent transition radiation generated from an ultrashort electron bunching beam is reported.During this experiment,the window for THz transmission from ultrahigh vacuum to free air is tested.The compact measurement system which can simultaneously test the THz wave power and frequency is built and proofed.With the help of improved Martin-Puplett interferometer and Kramers-Krong transform,the longitudinal bunch length is measured.The results show that the peak power of THz radiation wave is more than 80 kW,and its radiation frequency is from 0.1 THz to 1.5 THz. 相似文献
9.
There are many methods based on linac for THz radiation production.As one of the options for the Beijing Advanced Light, an ERL test facility is proposed for THz radiation.In this test facility, there are 4 kinds of methods to produce THz radiation: coherent synchrotron radiation (CSR), synchrotron radiation (SR), low gain FEL oscillator, and high gain SASE FEL.In this paper, we study the characteristics of the 4 kinds of THz light sources. 相似文献
10.
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
11.
We report the generation of tunable, narrow-band, few-cycle and multicycle coherent terahertz (THz) pulses from a temporally modulated relativistic electron beam. We demonstrate that the frequency of the THz radiation and the number of the oscillation cycles of the THz electric field can be tuned by changing the modulation period of the electron beam through a temporally shaped photocathode drive laser. The central frequency of the THz spectrum is tunable from ~0.26 to 2.6 THz with a bandwidth of ~0.16 THz. 相似文献
12.
We report the observation of enhanced coherent Smith-Purcell radiation (SPR) at terahertz (THz) frequencies from a train of picosecond bunches of 15 MeV electrons passing above a grating. SPR is more intense than other sources, such as transition radiation, by a factor of Ng, the number of grating periods. For electron bunches that are short compared with the radiation wavelength, coherent emission occurs, enhanced by a factor of Ne, the number of electrons in the bunch. The electron beam consists of a train of Nb bunches, giving an energy density spectrum restricted to harmonics of the 17 GHz bunch train frequency, with an increased energy density at these frequencies by a factor of Nb. We report the first observation of SPR displaying all three of these enhancements, NgNeNb. This powerful SPR THz radiation can be detected with a high signal to noise ratio by a heterodyne receiver. 相似文献
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15.
M. Labat M. Hosaka A. Mochihashi M. Shimada M. Katoh G. Lambert T. Hara Y. Takashima M. E. Couprie 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(1):187-200
Among the attractive coherent light sources resulting from the interaction between femtosecond lasers and relativistic electron
beams, simultaneous Coherent Synchrotron Radiation (CSR) in the THz region, slicing and UV-VUV Coherent Harmonic Generation
(CHG) can be achieved on synchrotron radiation facilities. Recently, a Ti:Sa laser at high repetition rate (1 kHz) has been
seeded in the optical klystron of the Free Electron Laser at UVSOR-II (Okazaki, Japan). In this paper, the experimental set-up
allowing delivery of sub picosecond UV pulses from CHG, and TeraHertz radiation from CSR is described. We further focus on
the third coherent harmonic (266 nm) generated. The expected typical characteristics of this radiation, predicted by both
numerical and analytical models recalled here, are experimentally verified and several studies of the influence of the seed
laser on the output CHG intensity are reported. Such experiment enables UVSOR-II facility to produce in parallel short pulses
at two different colors, synchronized at high repetition rate with one single infrared laser: a unique set-up of great interest
for the facility users. 相似文献
16.
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
17.
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
18.
In this letter, we describe a coherent subpicosecond terahertz (THz) spectroscopy system based on nonresonant optical rectification for the generation of THz radiation. We studied the two-photon absorption (TPA) of ZnTe induced by femtosecond laser pulses via THz generation, and its influence on the generation of THz radiation. Experimental results demonstrated that the intensity of pump beam against TPA must be traded off to get an optimum generation of THz radiation. As an example, we measured absorption spectrum of water vapor by time-domain spectroscopy (TDS) in the frequency range from 0.5 to 2.5 THzwith a high overall accuracy. 相似文献
19.
A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the power, frequency spectrum. First experiments show the averaged power at THz to be about 20mW. 相似文献
20.
Yong Yin Yang Yan Yaxin Zhang Min Hu Renbin Zhong Shenggang Liu 《International Journal of Infrared and Millimeter Waves》2007,28(10):797-809
In the modern science and technology a compact and having enough output power terahertz radiation source working in room temperature
have earned great attention. This paper is devoted to utilize electron bunches stimulate Vavilov-Cherenkov Radiation (VCR)
in a special three-mirror quasi-optical cavity to generate coherent THz waves. This novel three-mirror quasi-optical resonant
cavity has the coaxial field pattern which enables field establish in this cavity effectively. The analytical theory of the
radiation exited by a train of electron bunches in the special kind of three-mirror cavity has been carried out and the coherent
VCR has been achieved by the computer simulation. All those shows that this method can be used to establish useful THz radiation
source by the normal electron gun and the commonly used microwave devices. 相似文献