1
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Epp D, Schröder B, Möller M, Ropers C. Gigahertz streaking and compression of low-energy electron pulses. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:024306. [PMID: 38566809 PMCID: PMC10987198 DOI: 10.1063/4.0000235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024]
Abstract
Although radio frequency (RF) technology is routinely employed for controlling high-energy pulses of electrons, corresponding technology has not been developed at beam energies below several kiloelectronvolts. In this work, we demonstrate transverse and longitudinal phase-space manipulation of low-energy electron pulses using RF fields. A millimeter-sized photoelectron gun is combined with synchronized streaking and compression cavities driven at frequencies of 0.5 and 2.5 GHz , respectively. The phase-controlled acceleration and deceleration of photoelectron pulses is characterized in the energy range of 50 -100 eV . Deflection from a transient space-charge cloud at a metal grid is used to measure a fourfold compression of 80 - eV electron pulses, from τ = 34 to τ = 8 ps pulse duration.
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Affiliation(s)
| | | | | | - Claus Ropers
- Author to whom correspondence should be addressed:. URL:https://www.mpinat.mpg.de/de/ropers
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2
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Peak Shift of Coherent Edge Radiation Spectrum Depending on Radio Frequency Field Phase of Accelerator. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12020626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Spectra of coherent edge radiation (CER) were observed at the S-band linac facility of Kyoto University Free Electron Laser. A local maximum was observed in the CER spectrum on-crest operation of the radio frequency (RF) field. As the phase of the RF field was shifted from the crest, the frequency of the maximum decreased, and the CER spectrum approached a spectrum of Gaussian-distributed electrons in a bunch. It was found that this strange spectrum can be explained by a model in which a satellite pulse exists around a main pulse in the electron bunch. Furthermore, it demonstrated that CER is an effective tool for monitoring the shape of the electron bunch.
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3
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Real-time ultrafast oscilloscope with a relativistic electron bunch train. Nat Commun 2021; 12:6851. [PMID: 34824264 PMCID: PMC8617034 DOI: 10.1038/s41467-021-27256-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 11/03/2021] [Indexed: 11/13/2022] Open
Abstract
The deflection of charged particles is an intuitive way to visualize an electromagnetic oscillation of coherent light. Here, we present a real-time ultrafast oscilloscope for time-frozen visualization of a terahertz (THz) optical wave by probing light-driven motion of relativistic electrons. We found the unique condition of subwavelength metal slit waveguide for preserving the distortion-free optical waveform during its propagation. Momentary stamping of the wave, transversely travelling inside a metal slit, on an ultrashort wide electron bunch enables the single-shot recording of an ultrafast optical waveform. As a proof-of-concept experiment, we successfully demonstrated to capture the entire field oscillation of a THz pulse with a sampling rate of 75.7 TS/s. Owing to the use of transversely-wide and longitudinally-short electron bunch and transversely travelling wave, the proposed “single-shot oscilloscope” will open up new avenue for developing the real-time petahertz (PHz) metrology. A travelling wave inside a metal slit can reveal its own waveform by probing deflecting motions of charged particles. Here, a real-time THz oscilloscope was demonstrated by utilizing the relativistic electrons and the subwavelength slit waveguide.
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4
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Measurement of bunch length and temporal distribution using accelerating radio frequency cavity in low-emittance injector. Sci Rep 2020; 10:18905. [PMID: 33144680 PMCID: PMC7609657 DOI: 10.1038/s41598-020-76054-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 10/20/2020] [Indexed: 11/26/2022] Open
Abstract
We demonstrate an experimental methodology for measuring the temporal distribution of pico-second level electron bunch with low energy using radial electric and azimuthal magnetic fields of an accelerating (\documentclass[12pt]{minimal}
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\begin{document}$$\hbox {TM}_{01}$$\end{document}TM01 mode) radio frequency (RF) cavity that is used for accelerating electron beams in a linear accelerator. In this new technique, an accelerating RF cavity provides a phase-dependent transverse kick to the electrons, resulting in the linear coupling of the trajectory angle with the longitudinal position inside the bunch. This method does not require additional devices on the beamline since it uses an existing accelerating cavity for the projection of the temporal distribution to the transverse direction. We present the theoretical basis of the proposed method and validate it experimentally in the compact-energy recovery linac accelerator at KEK. Measurements were demonstrated using a 2-cell superconducting booster cavity with a peak on-axis accelerating field (\documentclass[12pt]{minimal}
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\begin{document}$$E_0$$\end{document}E0) of 7.21 MV/m.
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5
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Honda Y, Shimada M, Aryshev A, Kato R, Miyajima T, Obina T, Takai R, Uchiyama T, Yamamoto N. Stimulated Excitation of an Optical Cavity by a Multibunch Electron Beam via Coherent-Diffraction-Radiation Process. PHYSICAL REVIEW LETTERS 2018; 121:184801. [PMID: 30444406 DOI: 10.1103/physrevlett.121.184801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Indexed: 06/09/2023]
Abstract
With a low emittance and short-bunch electron beam at a high repetition rate realized by a superconducting linac, stimulated excitation of an optical cavity at the terahertz spectrum range is shown. The electron beam passes through small holes in the cavity mirrors without being destroyed. A sharp resonance structure which indicates wideband stimulated emission via coherent diffraction radiation is observed while scanning the round-trip length of the cavity.
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Affiliation(s)
- Yosuke Honda
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Miho Shimada
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Alexander Aryshev
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Ryukou Kato
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Tsukasa Miyajima
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Takashi Obina
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Ryota Takai
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Takashi Uchiyama
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Naoto Yamamoto
- High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
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6
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Yu L, Li H, Wan W, Wei Z, Grzelakowski KP, Tromp RM, Tang WX. Space charge effects and aberrations on electron pulse compression in a spherical electrostatic capacitor. Ultramicroscopy 2017; 183:30-37. [PMID: 28712555 DOI: 10.1016/j.ultramic.2017.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 05/11/2017] [Accepted: 07/02/2017] [Indexed: 10/19/2022]
Abstract
The effects of space charge, aberrations and relativity on temporal compression are investigated for a compact spherical electrostatic capacitor (α-SDA). By employing the three-dimensional (3D) field simulation and the 3D space charge model based on numerical General Particle Tracer and SIMION, we map the compression efficiency for a wide range of initial beam size and single-pulse electron number and determine the optimum conditions of electron pulses for the most effective compression. The results demonstrate that both space charge effects and aberrations prevent the compression of electron pulses into the sub-ps region if the electron number and the beam size are not properly optimized. Our results suggest that α-SDA is an effective compression approach for electron pulses under the optimum conditions. It may serve as a potential key component in designing future time-resolved electron sources for electron diffraction and spectroscopy experiments.
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Affiliation(s)
- Lei Yu
- College of Materials Science and Engineering, Chongqing University, 400044 Chongqing, PR China
| | - Haibo Li
- College of Materials Science and Engineering, Chongqing University, 400044 Chongqing, PR China
| | - Weishi Wan
- College of Materials Science and Engineering, Chongqing University, 400044 Chongqing, PR China; Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Zheng Wei
- College of Materials Science and Engineering, Chongqing University, 400044 Chongqing, PR China
| | - Krzysztof P Grzelakowski
- Faculty of Microsystem Electronics and Photonics, Division of Microelectronics and Nanotechnology, Wroclaw University of Science and Technology, NCN Opus9 ST7/03815, Dluga Street 65, 53-633 Wroclaw, Poland
| | - Rudolf M Tromp
- IBM Research Division, T.J. Watson Research Center, Yorktown Heights, New York 10598, USA
| | - Wen-Xin Tang
- College of Materials Science and Engineering, Chongqing University, 400044 Chongqing, PR China; School of Physics, Monash University, Clayton, VIC 3800, Australia.
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7
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Veronese M, Appio R, Craievich P, Penco G. Absolute bunch length measurement using coherent diffraction radiation. PHYSICAL REVIEW LETTERS 2013; 110:074802. [PMID: 25166376 DOI: 10.1103/physrevlett.110.074802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Indexed: 06/03/2023]
Abstract
The longitudinal electron beam properties are of crucial importance for many types of frontier accelerators, from storage rings to free electron lasers and energy recovery linacs. For the online control of the machine and its stable operation, nondestructive shot by shot bunch length measurements are needed. Among the various instrumentations proposed and installed in accelerators worldwide, the ones based on the measurement of the coherent radiation power represent the simplest and the more robust tools for operational control. The major limitation of these systems is that they usually can provide only relative bunch length estimation. In this Letter we present a novel experimental methodology to self-calibrate a simple equipment based on diffraction radiation from a gap providing a measurement of the second order moment of the longitudinal distribution. We present the theoretical basis of the proposed approach and validate it through a detailed campaign of measurements.
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Affiliation(s)
- Marco Veronese
- Elettra-Sincrotrone Trieste S.C.p.A. di interesse nazionale, Strada Statale 14-km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Roberto Appio
- Elettra-Sincrotrone Trieste S.C.p.A. di interesse nazionale, Strada Statale 14-km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Paolo Craievich
- Elettra-Sincrotrone Trieste S.C.p.A. di interesse nazionale, Strada Statale 14-km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Giuseppe Penco
- Elettra-Sincrotrone Trieste S.C.p.A. di interesse nazionale, Strada Statale 14-km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy
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8
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Tokita S, Hashida M, Inoue S, Nishoji T, Otani K, Sakabe S. Single-shot femtosecond electron diffraction with laser-accelerated electrons: experimental demonstration of electron pulse compression. PHYSICAL REVIEW LETTERS 2010; 105:215004. [PMID: 21231312 DOI: 10.1103/physrevlett.105.215004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Indexed: 05/30/2023]
Abstract
We report the first experimental demonstration of longitudinal compression of laser-accelerated electron pulses. Accelerated by a femtosecond laser pulse with an intensity of 10¹⁸ W/cm², an electron pulse with an energy of around 350 keV and a relative momentum spread of about 10⁻² was compressed to a 500-fs pulse at a distance of about 50 cm from the electron source by using a magnetic pulse compressor. This pulse was used to generate a clear diffraction pattern of a gold crystal in a single shot. This method solves the space-charge problem in ultrafast electron diffraction.
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Affiliation(s)
- Shigeki Tokita
- Advanced Research Center for Beam Science, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
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9
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Dodin IY, Fisch NJ. Stochastic extraction of periodic attosecond bunches from relativistic electron beams. PHYSICAL REVIEW LETTERS 2007; 98:234801. [PMID: 17677909 DOI: 10.1103/physrevlett.98.234801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Indexed: 05/16/2023]
Abstract
Intense laser waves can form a time-dependent gate, which transmits or reflects particles depending on their initial phases. When faced by a relativistic electron beam, such a barrier slices it by randomly scattering all but some particles, which nearly conserve their velocity. Subfemtosecond or attosecond periodic electron bunches are then formed downstream and can be used, for example, to generate coherent x rays via Thomson backscattering of the laser light.
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Affiliation(s)
- I Y Dodin
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
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10
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Glinec Y, Faure J, Norlin A, Pukhov A, Malka V. Observation of fine structures in laser-driven electron beams using coherent transition radiation. PHYSICAL REVIEW LETTERS 2007; 98:194801. [PMID: 17677622 DOI: 10.1103/physrevlett.98.194801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Indexed: 05/16/2023]
Abstract
We have measured the coherent optical transition radiation emitted by an electron beam from laser-plasma interaction. The measurement of the spectrum of the radiation reveals fine structures of the electron beam in the range 400-1000 nm. These structures are reproduced using an electron distribution from a 3D particle-in-cell simulation and are attributed to microbunching of the electron bunch due to its interaction with the laser field. When the radiator is placed closer to the interaction point, spectral oscillations have also been recorded, signature of the interference of the radiation produced by two electron bunches delayed by 74 fs. The second electron bunch duration is shown to be ultrashort to match the intensity level of the radiation. Whereas transition radiation was used at longer wavelengths in order to estimate the electron bunch length, this study focuses on the ultrashort structures of the electron beam.
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Affiliation(s)
- Y Glinec
- Laboratoire d'Optique Appliquée - ENSTA, UMR 7639, CNRS, Ecole Polytechnique, 91761 Palaiseau, France
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11
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Woods KN, Lee SA, Holman HYN, Wiedemann H. The effect of solvent dynamics on the low frequency collective motions of DNA in solution and unoriented films. J Chem Phys 2006; 124:224706. [PMID: 16784300 DOI: 10.1063/1.2200349] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Infrared spectroscopy is used to probe the dynamics of in vitro samples of DNA prepared as solutions and as solid unoriented films. The lowest frequency DNA mode identified in the far-infrared spectra of the DNA samples is found to shift in frequency when the solvent influence in the hydration shell is altered. The lowest frequency mode also has characteristics that are similar to beta-relaxations identified in other glass forming polymers.
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Affiliation(s)
- K N Woods
- Ecology Department, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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12
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Holldack K, Khan S, Mitzner R, Quast T. Femtosecond terahertz radiation from femtoslicing at BESSY. PHYSICAL REVIEW LETTERS 2006; 96:054801. [PMID: 16486938 DOI: 10.1103/physrevlett.96.054801] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Indexed: 05/06/2023]
Abstract
Femtosecond far-infrared radiation pulses in the THz spectral range were observed as a consequence of the energy modulation of 1.7 GeV electrons by femtosecond laser pulses in the BESSY storage ring in order to generate femtosecond x-ray pulses ("femtoslicing"). In addition to being crucial for diagnostics of the laser-electron interaction, the THz radiation itself is useful for experiments where intense ultrashort THz pulses of well-defined temporal and spectral characteristics are required.
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Affiliation(s)
- K Holldack
- Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung m.b.H. (BESSY), Albert-Einstein-Strasse 15, 12489 Berlin, Germany.
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13
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van Tilborg J, Schroeder CB, Filip CV, Tóth C, Geddes CGR, Fubiani G, Huber R, Kaindl RA, Esarey E, Leemans WP. Temporal characterization of femtosecond laser-plasma-accelerated electron bunches using terahertz radiation. PHYSICAL REVIEW LETTERS 2006; 96:014801. [PMID: 16486463 DOI: 10.1103/physrevlett.96.014801] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Indexed: 05/06/2023]
Abstract
The temporal profile of relativistic laser-plasma-accelerated electron bunches has been characterized. Coherent transition radiation at THz frequencies, emitted at the plasma-vacuum boundary, was measured through electro-optic sampling. Frequencies up to the crystal detection limit of 4 THz were observed. Comparison between data and theory indicates that THz radiation from bunches with structure shorter than approximately = 50 fs (root-mean-square) is emitted. The measurement demonstrates both shot-to-shot stability of the laser-plasma accelerator and femtosecond synchronization between bunch and probe beam.
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Affiliation(s)
- J van Tilborg
- Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA
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14
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Woods KN, Wiedemann H. The influence of chain dynamics on the far-infrared spectrum of liquid methanol-water mixtures. J Chem Phys 2005; 123:134507. [PMID: 16223314 DOI: 10.1063/1.2000239] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Far-infrared-absorption spectroscopy has been used to study the low-frequency (<or=100 cm-1) intermolecular modes of methanol in mixtures with water. With the aid of a first-principles molecular-dynamics simulation on an equivalent system, a detailed understanding about the origin of the low-frequency IR modes has been established. The total dipole spectrum from the simulation suggests that the bands appearing in the experimental spectra at approximately 55 and 70 cm-1 in methanol and methanol-rich mixtures arise from both fluctuations and torsional motions occurring within the methanol hydrogen-bonded chains. The influence of these modes on both the solvation dynamics and the relaxation mechanisms in the liquid is discussed within the context of recent experimental and theoretical results that have emerged from studies focusing on the short-time dynamics in the methanol hydrogen bond network.
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Affiliation(s)
- K N Woods
- BioPhysics Program, Stanford University, Stanford, California 94309, USA.
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15
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Woods KN, Wiedemann H. The influence of chain dynamics on the far-infrared spectrum of liquid methanol. J Chem Phys 2005; 123:134506. [PMID: 16223313 DOI: 10.1063/1.2000238] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Far-infrared-absorption spectroscopy is used to investigate the low-frequency (<or=100 cm-1) intermolecular interactions in liquid methanol. Using an intense source of far-infrared radiation, modes are elucidated at approximately 30 and 70 cm-1 in the absorption spectrum. These modes are believed to arise from intermolecular bending and librational motions, respectively, and are successfully reproduced in an ab initio molecular-dynamics simulation of methanol.
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Affiliation(s)
- K N Woods
- BioPhysics Program, Stanford University, Stanford, California 94309, USA.
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16
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Woods K, Wiedemann H. The relationship between dynamics and structure in the far infrared absorption spectrum of liquid water. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.06.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Schroeder CB, Esarey E, Van Tilborg J, Leemans WP. Theory of coherent transition radiation generated at a plasma-vacuum interface. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:016501. [PMID: 14995729 DOI: 10.1103/physreve.69.016501] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Indexed: 05/24/2023]
Abstract
Transition radiation generated by an electron beam, produced by a laser wakefield accelerator operating in the self-modulated regime, crossing the plasma-vacuum boundary is considered. The angular distributions and spectra are calculated for both the incoherent and the coherent radiation. The effects of the longitudinal and transverse momentum distributions on the differential energy spectra are examined. Diffraction radiation from the finite transverse extent of the plasma is considered and shown to strongly modify the spectra and energy radiated for long-wavelength radiation. This method of transition radiation generation has the capability of producing high peak power terahertz radiation, of order 100 microJ/pulse at the plasma-vacuum interface, which is several orders of magnitude beyond current state-of-the-art terahertz sources.
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Affiliation(s)
- C B Schroeder
- Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA
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18
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Leemans WP, Geddes CGR, Faure J, Tóth C, van Tilborg J, Schroeder CB, Esarey E, Fubiani G, Auerbach D, Marcelis B, Carnahan MA, Kaindl RA, Byrd J, Martin MC. Observation of terahertz emission from a laser-plasma accelerated electron bunch crossing a plasma-vacuum boundary. PHYSICAL REVIEW LETTERS 2003; 91:074802. [PMID: 12935022 DOI: 10.1103/physrevlett.91.074802] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2003] [Indexed: 05/24/2023]
Abstract
Coherent radiation in the 0.3-3 THz range has been generated from femtosecond electron bunches at a plasma-vacuum boundary via transition radiation. The bunches produced by a laser-plasma accelerator contained 1.5 nC of charge. The THz energy per pulse within a limited 30 mrad collection angle was 3-5 nJ and scaled quadratically with bunch charge, consistent with coherent emission. Modeling indicates that this broadband source produces about 0.3 microJ per pulse within a 100 mrad angle, and that increasing the transverse plasma size and electron beam energy could provide more than 100 microJ/pulse.
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Affiliation(s)
- W P Leemans
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720, USA
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19
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Qian BL, Elsayed-Ali HE. Acceleration element for femtosecond electron pulse compression. PHYSICAL REVIEW E 2002; 65:046502. [PMID: 12006037 DOI: 10.1103/physreve.65.046502] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2001] [Indexed: 11/07/2022]
Abstract
An acceleration element is proposed for compressing the electron pulse duration in a femtosecond photoelectron gun. The element is a compact metal cavity with curved-shaped walls. An external voltage is applied to the cavity where a special electric field forms in such a way that the slow electrons in the electron pulse front are accelerated more than the fast electrons, and consequently the electron pulse duration will be compressed. The distribution of the electric field inside the acceleration cavity is analyzed for the geometry of the cavity. The electron dynamics in this acceleration cavity is also investigated numerically. Numerical results show that the electron pulse front and pulse duration can be improved by compensating for the effects of space charge and the initial energy spread of photoelectrons with a Lambertian angular distribution. Depending on the design parameters and the shape of the electron pulse, for a femtosecond electron gun with an electron energy of 30 keV, 10(3) electrons per pulse, and an electron drift length of 40 cm, the electron pulse duration can be reduced from 550 to 200 fs when using a compensating cavity with an average radius of 1.7 and 5.6 cm in length. Electron pulses shorter than 200 fs can be achieved if the length of the drift region is reduced.
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Affiliation(s)
- Bao-Liang Qian
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, Virginia 23529-0256, USA
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20
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Reitsma AJ, Goloviznin VV, Kamp LP, Schep TJ. Simulation of laser wakefield acceleration of an ultrashort electron bunch. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 63:046502. [PMID: 11308961 DOI: 10.1103/physreve.63.046502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2000] [Indexed: 05/23/2023]
Abstract
The dynamics of the acceleration of a short electron bunch in a strong plasma wave excited by a laser pulse in a plasma channel is studied both analytically and numerically in slab geometry. In our simulations, a fully nonlinear, relativistic hydrodynamic description for the plasma wave is combined with particle-in-cell methods for the description of the bunch. Collective self-interactions within the bunch are fully taken into account. The existence of adiabatic invariants of motion is shown to have important implications for the final beam quality. Similar to the one-dimensional case, the natural evolution of the bunch is shown to lead, under proper initial conditions, to a minimum in the relative energy spread.
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Affiliation(s)
- A J Reitsma
- Technische Universiteit Eindhoven, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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21
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Yan X, MacLeod AM, Gillespie WA, Knippels GM, Oepts D, Seidel W. Subpicosecond electro-optic measurement of relativistic electron pulses. PHYSICAL REVIEW LETTERS 2000; 85:3404-3407. [PMID: 11030907 DOI: 10.1103/physrevlett.85.3404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2000] [Indexed: 05/23/2023]
Abstract
Time-resolved measurements of the transverse electric field associated with relativistic electron bunches are presented. Using an ultrafast electro-optic sensor close to the electron beam, the longitudinal profile of the electric field was measured with subpicosecond time resolution and without time-reversal ambiguity. Results are shown for two cases: inside the vacuum beam line in the presence of wake fields, and in air behind a beryllium window, effectively probing the near-field transition radiation. Especially in the latter case, reconstruction of the longitudinal electron bunch shape is straightforward.
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Affiliation(s)
- X Yan
- School of Science and Engineering, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, United Kingdom
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Schroeder CB, Lee PB, Wurtele JS, Esarey E, Leemans WP. Generation of ultrashort electron bunches by colliding laser pulses. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1999; 59:6037-47. [PMID: 11969588 DOI: 10.1103/physreve.59.6037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/1998] [Revised: 01/14/1999] [Indexed: 04/18/2023]
Abstract
A proposed laser-plasma-based relativistic electron source [E. Esarey et al., Phys. Rev. Lett. 79, 2682 (1997)] using laser-triggered injection of electrons is investigated. The source generates ultrashort electron bunches by dephasing and trapping background plasma electrons undergoing fluid oscillations in an excited plasma wake. The plasma electrons are dephased by colliding two counterpropagating laser pulses which generate a slow phase velocity beat wave. Laser pulse intensity thresholds for trapping and the optimal wake phase for injection are calculated. Numerical simulations of test particles, with prescribed plasma and laser fields, are used to verify analytic predictions and to study the longitudinal and transverse dynamics of the trapped plasma electrons. Simulations indicate that the colliding laser pulse injection scheme has the capability to produce relativistic femtosecond electron bunches with fractional energy spread of order a few percent and normalized transverse emittance less than 1 mm mrad using 1 TW injection laser pulses.
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Affiliation(s)
- C B Schroeder
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
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Leemans WP, Schoenlein RW, Volfbeyn P, Chin AH, Glover TE, Balling P, Zolotorev M, Kim KJ, Chattopadhyay S, Shank CV. X-Ray Based Subpicosecond Electron Bunch Characterization Using 90 degrees Thomson Scattering. PHYSICAL REVIEW LETTERS 1996; 77:4182-4185. [PMID: 10062469 DOI: 10.1103/physrevlett.77.4182] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Schoenlein RW, Leemans WP, Chin AH, Volfbeyn P, Glover TE, Balling P, Zolotorev M, Kim KJ, Chattopadhyay S, Shank CV. Femtosecond X-ray Pulses at 0.4 A Generated by 90 Thomson Scattering: A Tool for Probing the Structural Dynamics of Materials. Science 1996. [DOI: 10.1126/science.274.5285.236] [Citation(s) in RCA: 371] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Wang XJ, Qiu X, Ben-Zvi I. Experimental observation of high-brightness microbunching in a photocathode rf electron gun. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:R3121-R3124. [PMID: 9965628 DOI: 10.1103/physreve.54.r3121] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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Lihn H, Kung P, Settakorn C, Wiedemann H, Bocek D. Measurement of subpicosecond electron pulses. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:6413-6418. [PMID: 9965002 DOI: 10.1103/physreve.53.6413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Lihn H, Kung P, Settakorn C, Wiedemann H, Bocek D, Hernandez M. Observation of stimulated transition radiation. PHYSICAL REVIEW LETTERS 1996; 76:4163-4166. [PMID: 10061217 DOI: 10.1103/physrevlett.76.4163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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28
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Carlsten BE, Russell SJ. Subpicosecond compression of 0.1-1 nC electron bunches with a magnetic chicane at 8 MeV. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:R2072-R2075. [PMID: 9964610 DOI: 10.1103/physreve.53.r2072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Kimel I, Elias LR. Coherent Radiation Reaction in Free-Electron Sources. PHYSICAL REVIEW LETTERS 1995; 75:4210-4213. [PMID: 10059847 DOI: 10.1103/physrevlett.75.4210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Swartz JC, Guenther BD, Guo W, Jones CR, Kosai H, Dutta JM. Nondestructive diagnostics for relativistic picosecond bunched electron beams. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1995; 52:5416-5424. [PMID: 9964039 DOI: 10.1103/physreve.52.5416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Lai R, Happek U, Sievers AJ. Measurement of the longitudinal asymmetry of a charged particle bunch from the coherent synchrotron or transition radiation spectrum. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 50:R4294-R4297. [PMID: 9962613 DOI: 10.1103/physreve.50.r4294] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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