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70 papers
| title: | A Proposal for an X-Ray Free-Electron Laser Oscillator with an Energy-Recovery Linac |
| format: | journal article |
| year: | 2008 |
| 3 authors: | | | |
| abstract: | We show that a free-electron laser oscillator generating x rays with wavelengths of about 1 A ̊ is feasible using ultralow emittance electron beams of a multi-GeV energy-recovery linac, combined with a low-loss crystal cavity. The device will produce x-ray pulses with 109 photons at a repetition rate of 1–100 MHz. The pulses are temporarily and transversely coherent, with a rms bandwidth of about 2 meV, and rms pulse length of about 1 ps. |
| keywords: | pbpl prl |
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| title: | Beam compression experiments using the UCLA/ATF compressor |
| format: | conference procceeding |
| conference: | |
| year: | 2006 |
| 13 authors: | | | | | | | | | | | | | |
| abstract: | We review recent experimental results from the BNL ATF using the compressor built by UCLA. The measurements discussed include: first observation of short wavelength coherent edge radiation angular/wavelength spectrum and spectrum, sub-100 fsec pulse-length coherent transition autocorrelation measurements, and longitudinal and transverse phase space distortions. Extension of these measurements, as well as those which can be made possible by a new X-band traveling wave deflector being developed in an industrial collaboration, are examined. |
| keywords: | quindi |
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| title: | Magnetic Chicane Radiation Studies at the BNL ATF |
| format: | conference procceeding |
| conference: | |
| year: | 2006 |
| 11 authors: | | | | | | | | | | | |
| abstract: | Radiation emitted by relativistic electrons traversing the magnetic field gradients of a chicane bunch compressor has been studied in an attempt to characterize coherent edge radiation (CER). The studies performed at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL) include frequency spectrum, angular distribution, and polarization measurements. A reconstruction of the longitudinal charge profile from the measured spectrum shows that the bunch has been compressed to approximately 30 μm FWHM, with a peak current exceeding 1.5 kA. Measurements of radiation from the short pulses are compared to predictions from QUINDI, a new simulation code developed at UCLA to model the radiation. |
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| title: | The LCLS Single-shot Relative Bunch Length Monitor System |
| format: | conference procceeding |
| conference: | Erice 2005 |
| year: | 2006 |
| 4 authors: | | | | |
| abstract: | The Particle Beam Physics Lab (PBPL) at UCLA is developing a single-shot relative bunch length monitor system for the Linac Coherent Light Source (LCLS) X-ray Free Electron Laser at SLAC. To ensure high-quality lasing, feedback systems are needed. The bunch length monitor system will be a crucial part of the linac longitudinal feedback system, which is necessary to keep the final peak beam current stable. The system will consist of two multi-channel single-shot grating polychromators, one after each bunch compressor, and will use the coherent synchrotron radiation (CSR) or coherent edge radiation (CER) from bunch compressor chicane dipole magnets. Details of the system will be presented, and the system will be compared to alternatives. Plans for testing and integration into the LCLS beamline will be presented as well. |
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| title: | Observation of Anomalously Large Spectral Bandwidth in a High-Gain Self-Amplified Spontaneous Emission Free Elctron Laser |
| format: | journal article |
| year: | 2005 |
| 14 authors: | | | | | | | | | | | | | | |
| abstract: | Observation of ultrawide bandwidth, up to 15% full-width, high-gain operation of a self-amplified spontaneous emission free-election laser (SASE FEL) is reported. This type of lasing is obtained with a strongly chirped beam (E=E 1:7%) emitted from the accelerator. Because of nonlinear pulse compression during transport, a short, high current bunch with strong mismatch errors is injected into the undulator, giving high FEL gain. Start-to-end simulations reproduce key features of the measurements and provide insight into mechanisms, such as angular spread in emitted photon and electron trajectory distributions, which yield novel features in the radiation spectrum. |
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| title: | Recent Results from and Future Plans for the VISA II SASE FEL |
| format: | conference procceeding |
| conference: | 2005 Particle Accelerator Conference |
| year: | 2005 |
| 19 authors: | | | | | | | | | | | | | | | | | | | |
| abstract: | The VISA II (Visible to Infrared SASE Amplifier) project, a consequent experiment to the succesful VISA enterprise, entails the use of a chirped electron beam to drive a high gain SASE FEL. The resulting ultra-short pulses will be characterized using an advanced FROG (Frequency Resolved Optical Gating) technique, as well as a double differential spectrum (angle/wavelength) diagnostic. Implementation of sextupole corrections to the longitudinal aberrations affecting the high energy-spread chirped beam during transport to the VISA undulator is studied. Start-end simulations, including radiation diagnostics, are discussed. Initial experimental results involving a highly chirped beam transported without sextupole corrections, the resulting high gain lasing, and computational analysis are briefly reported. |
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| title: | Observation of Anomalously Large Spectral Bandwidth in a High Gain Self-amplified Spontaneous Emission Free-Electron Laser |
| format: | preprint |
| year: | 2005 |
| 14 authors: | | | | | | | | | | | | | | |
| abstract: | Observation of ultra-wide bandwidth, up to a full width of 15%, high-gain operation of a self-amplified spontaneous emission free election laser (SASE FEL) is reported. This type of lasing is obtained with a strongly chirped beam (~ 1.7%) emitted from the accelerator. Because of non-linear pulse compression during beam transport, a short, high current pulse with strong mismatch errors is injected into the undulator, bringing about high FEL gain. Start-end simulations reproduce key features of the measured results, and provide insight into mechanisms, such as angular spread in both emitted photon and electron trajectory distributions, which yield novel features in the radiation spectrum. |
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| title: | Recent Results from and Future Plans for the VISA II SASE FEL |
| format: | preprint |
| year: | 2005 |
| 19 authors: | | | | | | | | | | | | | | | | | | | |
| abstract: | The VISA II (Visible to Infrared SASE Amplifier) project, a consequent experiment to the succesful VISA enterprise, entails the use of a chirped electron beam to drive a high gain SASE FEL. The resulting ultra-short pulses will be characterized using an advanced FROG (Frequency Resolved Optical Gating)technique, as well as a double differential spectrum (angle/wavelength) diagnostic. Implementation of sextupole corrections to the longitudinal aberrations affecting the high energy-spread chirped beam during transport to the VISA undulator is studied. Start-end simulations, including radiation diagnostics, are discussed. Initial experimental results involving a highly chirped beam transported without sextupole corrections, the resulting high gain lasing, and computational analysis are briefly reported. |
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| title: | Development of X-ray Free-electron Lasers |
| format: | unknown |
| year: | 2004 |
| 2 authors: | | |
| abstract: | We review and discuss the theoretical and experimental work that has led to the development of short wavelength free-electron lasers operating as single pass amplifiers, starting from the spontaneous undulator radiation, in the self amplified spontaneous emission mode. This work has led to several projects to build this type of free-electron lasers operating at a wavelength of about 0.1 nm, producing coherent X-ray pulses with an unprecedented brilliance and peak power, and pulse length in the femtosecond range. One such project, the LCLS, is presently under construction and is expected to be operational in 2008. |
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| title: | Calculation of Coherent Radiation from Ultra-short Electron Beams Using a Li |
| format: | journal article |
| year: | 2004 |
| 6 authors: | | | | | | |
| abstract: | The coherent radiation emitted by electrons in high brightness beam-based experiments is important from the viewpoints of both radiation source development, and the understanding and diagnosing the basic physical processes important in beam manipulations at high intensity. While much theoretical work has been developed to aid in calculating aspects of this class of radiation, these methods do not often produce accurate information concerning the experimentally relevant aspects of the radiation. At UCLA, we are particularly interested in coherent synchrotron radiation and the related phenomena of coherent edge radiation, in the context of a fs-beam chicane compression experiment at the BNL ATF. To analyze this and related problems,we have developed aprogramthat acts as an extension to the Li |
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| title: | Design and Operation of Pegasus Thermionic Cathode |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 6 authors: | | | | | | |
| abstract: | A new thermionic cathode has been developed and installed for use on The PEGASUS plane wave transformer injector. The novel design of the LaB6 cathode allows for thermionic emission as well as photoinjector operation. Test stand measurements as well as in situ operational experience are reported. |
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| title: | Design and Status of the VISA II Experiment |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 12 authors: | | | | | | | | | | | | |
| abstract: | VISA II is the follow-up project to the successful Visible to Infrared SASE Amplifier (VISA) experiment at the Accelerator Test Facility (ATF) in Brookhaven National Lab (BNL). This paper will report the motivation for and status of the two main experiments associated with the VISA II program. One goal of VISA II is to perform an experimental study of the physics of a chirped beam SASE FEL at the upgraded facilities of the ATF. This requires a linearization of the transport line to preserve energy chirping of the electron beam at injection. The other planned project is a strong bunch compression experiment, where the electron bunch is compressed in the chicane, and the dispersive beamline transport, allowing studies of deep saturation. |
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| title: | Status of the UCLA PEGASUS Laboratory |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 6 authors: | | | | | | |
| abstract: | The PEGASUS laboratory is a versatile radiation facility dedicated to the advancement of novel concepts in beam physics. The installation of a new LaB$_6$ cathode will allow for both thermionic emission and photoinjection operation. The PEGASUS plane wave transformer injector has been conditioned to 20 MW of RF power. Recent operations show a 15 MeV dark current beam that will be used for beam radiation studies. An upgrade to the drive laser system has been explored and will be realized shortly. This paper will describe and report the status of the various subsystems of the PEGASUS laboratory and outline the experiments underway, such as innovative beam instrumentation, surface effects in optical transition radiation, Thomson scattering, and waveguide SASE FEL. |
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| title: | A Fast Method to Estimate the Gain of the Microbunch Instability in a Bunch Compressor |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 2 authors: | | |
| abstract: | For the users of the high-brightness radiation sources of free-electron lasers it is necessary to reduce the FEL pulse length to 10 fs and below for time-resolving pump and probe experiments. Although it can be achieved by conventional compression methods for the electron beam or the chirped FEL pulse, the technical realization is demanding. In this presentation we study the impact of undulator wakefields and how their properties can be used to reduced the amplifying part of the bunch to the desired length. Methods of actively controlling the wakefields are presented. |
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| title: | Theoretical evaluation of the LCLS X-Ray Free-Electron Laser performance |
| format: | conference procceeding |
| conference: | 25th International Free Electron Laser Conference |
| year: | 2003 |
| 4 authors: | | | | |
| abstract: | In this paper we evaluate the performance of the LCLS FEL, including all known physical effects from the electron source to the undulator exit which determine the X-ray pulse characteristics. The wavelength range considered is from the 15 to 1.5 Angstrom, with an extension to 0.5 Angstrom using the third harmonic. The results of this work have been useful to identify areas in the LCLS design where improvements could be made, thus optimizing the system performance. |
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| title: | Start-to-End Simulations for the LCLS X-Ray Free-Electron Laser |
| format: | conference procceeding |
| conference: | 25th International Free Electron Laser Conference |
| year: | 2003 |
| 7 authors: | | | | | | | |
| abstract: | The LCLS Free-Electron Lasers operates in the wavelength range of 1.5-15 Angstrom, using an electron beam with an energy between 4.5 and 14.5 GeV. The generation of the electron beam, the preservation of its brightness during acceleration and compression, and the amplififcation of the spontaneous radiation within the FEL can only be described by a consistent set of simulation codes. We preset the change in the FEL performance with respect to the LCLS design case, when various effects are included, altering the electron beam distribution and motion (e.g. wake fields, CSR, magnet misalignment or field errors of the undulator field). To distinguish the individual contribution of each effect, multiple start-end simulations are performed, including step by step additional effects and, thus, approaching a more and more realistic model of the LCLS FEL. |
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| title: | The FEL Program at the PEGASUS Injector |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 6 authors: | | | | | | |
| abstract: | The PEGASUS photo injector at UCLA can produce a photo electrons beam with a normalized emittance of 2 mm mrad at an energy of 12-15 MeV, capable of driving a Free-Electron Laser in the mid IR regime. The FEL program, associated with the PEGASUS injector and presented here, is based on a Self-Amplifying Spontaneous Emission (SASE) FEL. The studies focus on increasing the efficiency of an FEL by novel undulator design and compensation of diffraction effects, using waveguides of millimeter size. In this presentation we also discuss the possibility of the PEGASUS FEL as a THz user facility. |
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| title: | Pulse Length Control in an X-Ray FEL by Using Wakefields |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 3 authors: | | | |
| abstract: | For the users of the high-brightness radiation sources of free-electron lasers it is necessary to reduce the FEL pulse length to 10 fs and below for time-resolving pump and probe experiments. Although it can be achieved by conventional compression methods for the electron beam or the chirped FEL pulse, the technical realization is demanding. In this presentation we study the impact of undulator wakefields and how their properties can be used to reduced the amplifying part of the bunch to the desired length. Methods of actively controlling the wakefields are presented. |
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| title: | The UCLA Pegasus Plane-Wave Transformer Photoinjector |
| format: | conference procceeding |
| conference: | 2003 Particle Accelerator Conference |
| year: | 2003 |
| 6 authors: | | | | | | |
| abstract: | A photoinjector based on a multicell plane wave transformer accelerating structure has been commissioned at the UCLA Department of Physics' Pegasus Laboratory. Design and construction of the novel structure have been previously reported [J. Rosenzweig, et al. PAC Proceedings 1997], and recent operation with a thermionic cathode is being presented at this conference [P. Frigola, et al. these proceedings]. This paper describes the planned operation of the PWT gun as a photoinjector, including design and construction details of the drive laser. Progress to date and future plans are discussed. |
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| title: | Properties of the ultrashort gain length, self-amplified spontaneous emission free-electron laser in the linear regime and saturation |
| format: | journal article |
| year: | 2003 |
| 26 authors: | | | | | | | | | | | | | | | | | | | | | | | | | | |
| abstract: | VISA (Visible to Infrared SASE Amplifier) is a high-gain self-amplified spontaneous emission (SASE) free-electron laser (FEL), which achieved saturation at 840 nm within a single-pass 4-m undulator. The experiment was performed at the Accelerator Test Facility at BNL, using a high brightness 70-MeV electron beam. A gain length shorter than 18 cm has been obtained, yielding a total gain of 2x10(8) at saturation. The FEL performance, including the spectral, angular, and statistical properties of SASE radiation, has been characterized for different electron beam conditions. Results are compared to the three-dimensional SASE FEL theory and start-to-end numerical simulations of the entire injector, transport, and FEL systems. An agreement between simulations and experimental results has been obtained at an unprecedented level of detail. |
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| title: | Comparison of the coherent radiation-induced microbunching instability in a free-electron laser and a magnetic chicane |
| format: | journal article |
| year: | 2003 |
| 2 authors: | | |
| abstract: | A self-amplified spontaneous emission free-electron laser (SASE FEL) is a device which is based on the creation of a very intense, relativistic electron beam which has very little temperature in all three phase planes. The beam in this system is described as having "high brightness,'' and when it is bent repetitively in a magnetic undulator, undergoes a radiation-mediated microbunching instability. This instability can amplify the original radiation amplitude at a particular, resonant wavelength by many orders of magnitude. In order to obtain high brightness beams, it is necessary to compress them to obtain higher currents than available from the electron source. Compression is accomplished by the use of magnetic chicanes, which are quite similar to, if much longer than, a single period of the undulator. It should not be surprising that such chicanes also support a radiation-mediated microbunching interaction, which has recently been investigated, and has been termed coherent synchrotron radiation (CSR) instability. The purpose of this paper is to compare and contrast the characteristics of the closely related FEL and CSR microbunching instabilities. We show that a high-gain regime of the CSR instability exists which is formally similar to the FEL instability. |
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| title: | Free-Electron Simulations at Short Wavelengths |
| format: | preprint |
| year: | May 01, 2002 |
| 1 author: | |
| abstract: | Outline: FEL Simulations Overview Codes Shot-Noise Models Short Wavelength Effects Spontaneous Radiation Wake Fields Undulator Description Start-End Simulations |
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| title: | Gain Computation |
| format: | preprint |
| year: | April 24, 2002 |
| 1 author: | |
| abstract: | |
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| title: | Comparison of the FEL and CSR Instabilities |
| format: | preprint |
| year: | April 19, 2002 |
| 1 author: | |
| abstract: | FEL and CSR instabilities have same principle of interaction between electron beam and synchrotron radiation, but the signature is different for the different longitudinal scales. Beside the FEL these instabilities are regarded as degrading affects on the beam properties, imposing limitation on the operation range of the accelerator. |
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| title: | A fast method to estimate the gain of the microbunch instability in a bunch compressor |
| format: | conference procceeding |
| conference: | 24th International Free Electron Laser Conference |
| year: | 2003 |
| 2 authors: | | |
| abstract: | To reach high peak currents driving Free-Electron Lasers an initial chirped electron bunch is compressed in a bunch compressor. The interaction of the electron beam with its radiation field can yield a collective instability, which amplifies any initial modulation in the current profile. We present a model, which allows to derive an explicit analytical expression for the gain of the microbunch instability. The results are compared to those of the more complex analytical models. |
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| title: | Results of the VISA SASE FEL Experiment at 840 nm |
| format: | conference procceeding |
| conference: | 24th International Free Electron Laser Conference |
| year: | 2003 |
| 26 authors: | | | | | | | | | | | | | | | | | | | | | | | | | | |
| abstract: | VISA (Visible to Infrared SASE Amplifier) is a high-gain self-amplified spontaneous emission (SASE) free-electron laser (FEL), which achieved saturation at 840 nm within a single-pass 4-m undulator. A gain length shorter than 18 cm has been obtained, yielding the gain of 2x10(8) at saturation. The FEL performance, including the spectral, angular, and statistical properties of SASE radiation, has been characterized for different electron beam conditions. The results are compared to 3-D SASE FEL theory and start-to-end numerical simulations of the entire injector, transport, and FEL system. Detailed agreement between simulations and experimental results is obtained over the wide range of the electron beam parameters. |
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| title: | Status of the UCLA PEGASUS Injector Laboratory |
| format: | conference procceeding |
| conference: | 24th International Free Electron Laser Conference |
| year: | 2003 |
| 6 authors: | | | | | | |
| abstract: | The PEGASUS plane wave transformer injector has been conditioned to 20 MW of RF power. Initial operations show a 15 MeV dark current beam that will be used for beam radiation studies. The design of a new LaB_6 cathode will allow for both thermionic emission and photoinjection operation. Experiments currently planned include novel beam instrumentation, surface effects in optical transition radiation, and waveguide SASE FEL. |
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| title: | Pulse length control in an X-ray FEL by using wakefields |
| format: | conference procceeding |
| conference: | 24th International Free Electron Laser Conference |
| year: | 2003 |
| 3 authors: | | | |
| abstract: | For the users of the high-brightness radiation sources of free-electron lasers it is desirable to reduce the FEL pulse length to 10 fs and below for time-resolving pump and probe experiments. Although it can be achieved by conventional compression methods for the electron beam or the chirped FEL pulse, the technical realization is demanding. In this presentation we study the impact of longitudinal wakefields in the undulator and how their properties can be used to reduced the amplifying part of the bunch to the desired length. Methods of actively controlling the wakefields are presented. |
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| title: | Measurements of nonlinear harmonic radiation and harmonic microbunching in a visible SASE FEL |
| format: | conference procceeding |
| conference: | 24th International Free Electron Laser Conference |
| year: | 2003 |
| 13 authors: | | | | | | | | | | | | | |
| abstract: | The experimental characterization of nonlinear harmonic generation (NHG) and electron beam microbunching at saturation from a visible SASE FEL are presented in this report. The gain lengths, spectra and energies of NHG were experimentally measured up to the third harmonic, and agree with theoretical predictions. Electron beam microbunching in both the fundamental and the second harmonic as the function of the SASE output were experimentally observed over the full range of SASE gain. The bunching factors for both the fundamental (b(1)) and second harmonic (b(2)) were experimentally characterized at saturation. The microbunching data provides another test of SASE saturation as well as correlating the NHG and electron beam microbunching modes to the fundamental SASE. |
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| title: | Properties of an Ultra-Short Gain Length, Saturated, Self-Amplified Spontaneous Emission FEL |
| format: | preprint |
| year: | 2002 |
| 26 authors: | | | | | | | | | | | | | | | | | | | | | | | | | | |
| abstract: | The VISA experiment, conducted at the BNL Accelerator Test Facility (ATF), has studied the properties of SASE FEL process in a saturating system. The experiment utilized a high brightness electron beam and a strong focusing undulator. Saturated gain greater than 108, with a power gain length below 18 cm, was obtained at 840 nm. Measurements of FEL gain, spectral and angular properties of SASE radiation are reported, and the results are compared to theory and to start-to-end simulations of the system. FEL performance was found critically dependent on the compression of the electron beam. |
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| title: | Fundamental and harmonic microbunching in a high-gain self-amplified spontaneous-emission free-electron laser |
| format: | unknown |
| year: | 2002 |
| 13 authors: | | | | | | | | | | | | | |
| abstract: | Electron beam microbunching in both the fundamental and second harmonic in a high-gain self-amplified spontaneous emission free-electron laser (SASE FEL) was experimentally characterized using coherent transition radiation. The microbunching factors for both modes (b1 and b2) approach unity, an indication of FEL saturation. These measurements are compared to the predictions of FEL simulations. The simultaneous capture of the microbunching and SASE radiation for individual micropulses correlate the longitudinal electron beam structure with the FEL gain. |
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| title: | Experimental characterization of nonlinear harmonic radiation from a visible self-amplified spontaneous emission free-electron laser at saturation |
| format: | unknown |
| year: | 2002 |
| 12 authors: | | | | | | | | | | | | |
| abstract: | Nonlinear harmonic radiation was observed using the VISA self-amplified, spontaneous emission (SASE) free-electron laser (FEL) at saturation. The gain lengths, spectra, and energies of the three lowest SASE FEL modes were experimentally characterized. The measured nonlinear harmonic gain lengths and center spectral wavelengths decrease with harmonic number, n, which is consistent with nonlinear harmonic theory. Both the second and third nonlinear harmonics energies are about 1% of the fundamental energy. These experimental results demonstrate for the first time the feasibility of using nonlinear harmonic SASE FEL radiation to produce coherent, femtosecond X-rays. (33 References). |
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| title: | Chirped-beam two-stage free-electron laser for high-power femtosecond x-ray pulse generation |
| format: | journal article |
| year: | 2002 |
| 5 authors: | | | | | |
| abstract: | A method for generating femtosecond-duration x-ray pulses with a free-electron laser is presented. This method uses an energy-chirped electron beam propagating through an undulator to produce a frequency-chirped x-ray pulse by self-amplified spontaneous emission. A short temporal pulse is created by use of a monochromator to select a narrow radiation bandwidth. A second undulator is used to amplify the short-duration radiation. The radiation characteristics produced by a chirped-beam two-stage free-electron laser are calculated, and the performance of the chirped-beam two-stage option for the Linac Coherent Light Source is considered. |
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| title: | Fundamental and Harmonic Microbunching Measurements in a High-Gain, Self-Amplified, Spontaneous Emission Free-Electron Laser |
| format: | preprint |
| year: | 2002 |
| 13 authors: | | | | | | | | | | | | | |
| abstract: | The self-amplified, spontaneous emission free-electron laser (SASE-FEL) gain process is a collective instability which induces microbunching in the electron beam. Micro-bunching approaching unity at the fundamental FEL wavelength (845 nm), and its second harmonic, have been measured at the VISA FEL, at or near saturation. These measurements, which use the beam's coherent transition radiation (CTR) spectrum, are sompared to the predictions of FEL simulations. Comparison of shot-by-shot SASE and CTR signals firmly establishes the role of SASE in the development of microbunching harmonics. |
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| title: | Two-Stage Chirped-Beam SASE-FEL for High Power Femtosecond X-Ray Pulse Generation |
| format: | preprint |
| year: | December 10, 2001 |
| 5 authors: | | | | | |
| abstract: | |
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| title: | Status of the 3D Time-Dependent FEL Simulation Code GENESIS 1.3 |
| format: | conference procceeding |
| conference: | 23rd International Free Electron Laser Conference |
| year: | 2002 |
| 2 authors: | | |
| abstract: | Since its release in 1999 the 3D time-dependent code GENESIS 1.3 has become a helpful tool for the design-studies and analysis of a single-pass Free-Eelectron Lasers experiments. With the latest version new features have been added such as support for wake-fields and incoherent spontaneous radiation. In addition the more modular structure of the open-source code and the improved support of external imput files allow a better understanding of the code, supporting users who want to add new features to the code. |
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| title: | Chirped-beam two-stage SASE-FEL for high power femtosecond X-ray pulse generation |
| format: | conference procceeding |
| conference: | 23rd International Free Electron Laser Conference |
| year: | 2002 |
| 5 authors: | | | | | |
| abstract: | A method for generating femtosecond duration X-ray pulses using a single-pass free-electron laser (FEL) is presented. This method uses an energy-chirped electron beam propagating through an undulator to produce a frequency-chirped X-ray pulse through self-amplified spontaneous emission (SASE). After the undulator, we consider passing the radiation through a monochromator. The frequency is correlated to the longitudinal position within the pulse; therefore, by selecting a narrow bandwidth, a short temporal pulse will be transmitted. The short pulse radiation is used to seed a second undulator, where the radiation is amplified to saturation. In addition to short pulse generation, this scheme has the ability to control shot-to-shot fluctuations in the central wavelength due to electron beam energy jitter. We present calculations of the radiation characteristics produced by a chirped-beam two-stage SASE?FEL, and consider the performance of the chirped-beam two-stage option for the Linac Coherent Light Source. |
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| title: | Characterization of an 800 nm SASE FEL at saturation |
| format: | conference procceeding |
| conference: | 23rd International Free Electron Laser Conference |
| year: | 2002 |
| 24 authors: | | | | | | | | | | | | | | | | | | | | | | | | |
| abstract: | Visible to Infrared SASE Amplifier is a free electron laser (FEL) designed to saturate at a radiation wavelength of 800 nm within a 4 m long, strong focusing undulator. A large gain is achieved by driving the FEL with 72 MeV, high brightness beam of BNL's accelerator test facility. We present measurements that demonstrate saturation in addition to the frequency spectrum of the FEL radiation. Energy, gain length and spectral characteristics are compared and shown to agree with simulation and theoretical predictions. (16 References). |
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| title: | The BESSY FEL Project |
| format: | conference procceeding |
| conference: | 23rd International Free Electron Laser Conference |
| year: | 2002 |
| 20 authors: | | | | |