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in subjects: "Free Electron Lasers"

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A CW normal-conductive RF gun for free electron laser and energy recovery linac applications

Currently proposed energy recovery linac and high average power free electron laser projects require electron beam sources that can generate up to {approx} 1 nC bunch charges with less than 1 mmmrad normalized emittance at high repetition rates (greater than {approx} 1 MHz). Proposed sources are based around either high voltage DC or microwave RF guns, each with its particular set of technological limits and system complications. We propose an approach for a gun fully based on mature RF and mec… more

Date: October 8, 2008

Creator: Baptiste, Kenneth; Corlett, John; Kwiatkowski, Slawomir; Lidia, Steven; Qiang, Ji; Sannibale, Fernando et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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RF coupler for high-power CW FEL photoinjector

A high-current emittance-compensated RF photoinjector is a key enabling technology for a high-power CW FEL. The design presently under way is a 100-mA 2.5-cell {pi}-mode, 700-MHz, normal conducting demonstration CW RF photoinjector. This photoinjector will be capable of accelerating 3 nC per bunch with an emittance at the wiggler less than 10 mm-mrad. The paper presents results for the RF coupling from ridged wave guides to hte photoinjector RF cavity. The LEDA and SNS couplers inspired this 'd… more

Date: January 1, 2003

Creator: Kurennoy, S. (Sergey) & Young, L. M. (Lloyd M.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The First Lasing of 193 Nm Sase, 4th Harmonic Hghg and Esase at the Nsls Sdl.

The first lasing of three types of single-pass high-gain FELs, SASE at 193 nm, 4th harmonic HGHG at 199 nm and ESASE at the Source Development Lab (SDL) of Brookhaven National Laboratory (BNL) is reported. The saturation of 4th harmonic HGHG and ESASE FELs was observed. We also observed the spectral broadening and instability of the 4th harmonic HGHG.

Date: August 28, 2006

Creator: Wang, X. J.; Shen, Y.; Watanabe, T.; Murphy, J. B.; Rose, J. & Tsang, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Spectral measurements of the second harmonic of the SASE FEL radiation at APS.

We present the z-dependent spectral measurement results for the second harmonic of the SASE FEL radiation before and after saturation. The measurements were performed at the Advanced Photon Source FEL with the fundamental wavelength of 530 nm. The spectral properties of the second harmonic are compared with those of the fundamental and with the theoretical expectations.

Date: October 3, 2002

Creator: Sajaev, V. & Huang, Z.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Intra-cavity Thomson Scattering

The kW-class infrared (IR) free electron laser (FEL) at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) had the capability of producing intra-cavity Thomson scattering of the IR off the electron beam thus producing high average flux, sub-picosecond x-rays. We have measured these x-rays and demonstrated the energy tunability range from 3.5 keV to 18 keV. The corresponding flux and brightness have been estimated and will be discussed. In 2002, the FEL was disassembled and has b… more

Date: January 2003

Creator: Boyce, James

Item Type: Book

Partner: UNT Libraries Government Documents Department

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MIT microwiggler for free electron laser applications

A microwiggler-based FEL permits operation at shorter wavelengths with a reduction in the size and cost of the device. The MIT microwiggler is a pulsed ferromagnetic-core electromagnet with 70 periods of 8.8 mm each which generates an on-axis peak magnetic field of 4.2 kG. The pulse repetition rate is 0.5 Hz with FWHM 0.5 msec. The microwiggler is characterized by extensive tunability. We employed a novel tuning regimen through which the rms spread in peak amplitudes was reduced to 0.08 % the l… more

Date: July 1, 1995

Creator: Catravas, P.; Stoner, R.; Blastos, J.; Sisson, D.; Mastovsky, I.; Bekefi, G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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First Lasing of a High-Gain Harmonic Generation Free-Electron Laser Experiment.

We report on the first lasing of a high-gain harmonic generation (HGHG) free-electron laser (FEL). The experiment was conducted at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL). This is a BNL experiment in collaboration with the Advanced Photon Source (APS) at Argonne National Laboratory. A preliminary measurement gives a high-gain harmonic generation (HGHG) pulse energy that is 2 x 10{sup 7} times larger than the spontaneous radiation, In a purely self-amplified s… more

Date: September 11, 1999

Creator: Babzien, M.; Ben-Zvi, Ilan; Biedron, S. G.; DiMauro, L. F.; Douryan, A.; Galayda, J. N. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Production and test results of SC 3.9-GHz accelerating cavity at Fermilab

The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve beam performances for TTF-FEL facility. In the frame of collaboration Fermilab will provide DESY with a cryomodule containing a string of four cavities. In addition, a second cryomodule with one cavity will be fabricated for installation in the Fermilab photo-injector, which will be upgraded for the ILC accelerator test facility. In this paper we discuss the status of the cavity and coupler production and the first result of ca… more

Date: August 1, 2006

Creator: Khabiboulline, Timergali; Cooper, Charlie; Edwards, Helen; Foley, Mike; Gonin, Ivan; Mitchell, Donald et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Diffraction effects in the coherent transition radiation bunch length diagnostics

Diffraction effects in the Coherent Transition Radiation (CTR) bunch length diagnostics are considered for the A0 Photoinjector and the New Muon Laboratory (NML) injection module. The effects can cause a noticeable distortion of the measured CTR spectra depending on the experimental setup and the bunch parameters and resulting in errors of the bunch length measurements. Presented calculations show possible systematic errors in the bunch length in measurements based on the CTR spectra at A0 Phot… more

Date: August 1, 2007

Creator: Kazakevich, G.; Lebedev, V.; Nagaitsev, S. & /Fermilab

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Advanced photoinjector laser and microwave technologies. Final report

An overview of the design parameters of the compact, high gradient, high luminosity X-band (8.568 GHz) photoinjector facility currently being developed as a collaborative effort between LLNL and UC Davis, is followed by a more detailed description of each of its major subsystems : X-band rf gun, GHz repetition rate synchronously modelocked AlGaAs quantum well laser oscillator, and 8-pass Ti: Al{sub 2}O{sub 3} chirped pulse laser amplifier. The photoinjector uses a high quantum efficiency ({appr… more

Date: January 1, 1997

Creator: Hartemann, F. V.; Luhmann, N. C. Jr. & Talley, W. K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Free-Electron Lasers: Vacuum electronic generators of coherent radiation

Vacuum electronic sources have shown marked improvement since the invention of the magnetron before World War II, and dramatic increases in both average powers and frequencies have been achieved. Of course, much of these gains have been achieved by the development of different devices. The typical development pattern for a given device exhibits an initial period of rapid improvement followed by a plateau determined by technological or physical limitations on the concept. Slow wave devices such … more

Date: May 1, 1995

Creator: Neil, G. & Freund, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Modular approach to achieving the next-generation x-ray light source.

No Description Available.

Date: September 14, 2000

Creator: Biedron, S. G.; Milton, S. V. & Freund, Henry P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Solution to the initial value problem for a high-gain FEL via Van Kampen's method.

Using Van Kampen's normal mode expansion, we solve the initial value problem for a high-gain free-electron laser (FEL) described by the three-dimensional Maxwell-Klimontovich equations. An expression of the radiation spectrum is given for the process of coherent amplification and self-amplified spontaneous emission. It is noted that the input coupling coefficient for either process increases with the initial beam energy spread. The effective start-up noise is identified as the coherent fraction… more

Date: August 22, 2000

Creator: Huang, Z. & Kim, K. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Betatron radiation from electron beams in plasma focusing channels

Spontaneous radiation emitted from an electron undergoing betatron motion is a plasma focusing channel is analyzed and applications to plasma wakefield accelerator experiments and to the ion channel laser (ICL) are discussed. Important similarities and differences between a free electron laser (FEL) and in an ICL are delineated. It is shown that the frequency of spontaneous radiation is a strong function of the betatron strength parameter a{sub {beta}}, which plays a similar role to that of the… more

Date: June 1, 2000

Creator: Esarey, E.; Catravas, P. & Leemans, W. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Power Spectrum Calculation for the Cornell Wiggler a Sase Experiment at BNL

Recently the authors showed [I] that the widely used simulation code TDA3D, even though a single frequency code, can be used to determine the power spectrum in the SASE process with excellent approximation in the exponential growth regime. In this paper, they apply this method to the BNL Cornell Wiggler A SASE experiment as an example. When the gain is not very high, there are many modes in the radiation, which seems to make the analytical calculation very difficult. However, they show that the… more

Date: August 16, 1998

Creator: Yu, L. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Calculation of coherent emissions and gain from a prebunched Free Electron Laser

This report advances a theoretical model for the single pass growth of coherent radiation in a prebunched FEL system. The FEL system includes a radio frequency linear accelerator (fr linac) as the injector, a resonator cavity with a wiggler magnet, and two highly reflective plano-concave mirrors, typically 99{percent} of the radiation is reflected inside the resonator. The model is based upon the following assumptions: a) the electron beam is cold, b) a super- electron is a particle with {appro… more

Date: August 1, 1995

Creator: Treadwell, E. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Circular polarization with crossed-planar undulators in high gain FELs.

We propose a crossed undulator configuration for a high-gain free-electron laser to allow versatile polarization control. This configuration consists of a long (saturation length) planar undulator, a dispersive section, and a short (a few gain lengths) planar undulator oriented perpendicular to the first one. In the first undulator, a radiation component linearly polarized in the x-direction is amplified to saturation. In the second undulator, the x-polarized component propagates freely, while … more

Date: August 31, 1999

Creator: Kim, K. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Investigation of efficiency optimization in free electron lasers

The dynamics of trapped particles in the presence of the wiggler magnetic field and the electromagnetic radiation field in free electron lasers were investigated. From the results of computer simulations, it was found that, for a given set of parameters, the efficiency of energy extraction from the electron beam maximizes at a particular intensity of the electromagnetic radiation. Based on the physical argument of the dynamics of the trapped particles, a criterion which predicts accurately the … more

Date: January 1, 1979

Creator: Kwan, T. J. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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CHIRPED PULSE AMPLIFICATION OF HGHG-FEL FACILITY AT BNL.

The DUV-FEL facility has been in operation in High Gain Harmonic Generation (HGHG) mode for one year producing 266 nm output from 177 MeV electrons. In this paper we present preliminary results of the Chirped Pulse Amplification (CPA) of HGHG radiation. In the normal HGHG process, a 1 ps electron beam is seeded by chirped 9 ps long 800 nm Ti:Sapphire laser. The electron beam sees only a narrow fraction of the seed laser bandwidth. However, in the CPA case the seed laser pulse length is reduced … more

Date: September 8, 2003

Creator: DOYURAN,A. ET AL.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Hole-Coupled Resonators Tunable Infrared Free Electron Lasers

We review the study of hole-coupled resonators for broadly tunable free electron laser (FEL) applications. The mode profiles inside and outside the cavity, the diffraction losses at the mirror edges and intracavity apertures, the amount of useful power coupled through the holes, and the FEL gain are calculated for several dominant azimuthal and radial modes. The FEL interaction is taken into account by constructing a propagator similar to the Fresnel integral for free space propagation. It is f… more

Date: February 1, 1993

Creator: Xie, M. & Kim, K. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Numerical Simulation of Table-Top Tunable Smith-Purcell Teraherz Free-Electron Laser Operating in the Superradiant Regime

Terahertz (THz) radiation occupies a very large portion of the electromagnetic spectrum and has generated much recent interest due to its ability to penetrate deep into many organic materials without the damage associated with ionizing radiation such as x-rays. One path for generating copious amount of tunable narrow-band THz radiation is based on the Smith-Purcell free-electron laser (SPFEL) effect. In this Letter we propose a simple concept for a compact tunable SPFEL operating in the superra… more

Date: January 1, 2010

Creator: Prokop, C.; Piot, P.; Lin, M.C.; Stoltz, P. & U., /Fermilab /Northern Illinois

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Transverse-to-longitudinal Emittance-exchange with an Energy Chirped Beam

Emittance exchange has been proposed to increase the performance of free electron lasers by tailoring the phase space of an electron beam. The principle of emittance exchange - where the transverse phase space of the electron beam is exchanged with the longitudinal phase space - has been demonstrated recently at the A0 photoinjector. The experiment used a low charge bunch (250 pC) with no energy chirp. Theory predicts an improvement in the emittance exchange scheme when the incoming beam has an… more

Date: May 1, 2012

Creator: Thangaraj, J.; Ruan, J.; Johnson, A. S.; Thurman-Keup, R.; Lumpkin, A. H.; Santucci, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Mechanical design of the VISA undulator

As part of the research and development effort for a 4th generation light source, we have designed a 4-meter long Free-Electron Laser (FEL) undulator. The undulator will be installed at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory to conduct a Self-Amplified Spontaneous Emission (SASE) demonstration. The demonstration is called VISA, which stands for �Visible to Infrared SASE Amplifier.� The undulator consists of 440 permanent dipole magnets per meter which are supporte… more

Date: March 1, 1999

Creator: Bertolini, L; Carr, R; Duffy, P; Libkind, M; Ratowsky, G & Skarita, J

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Gamma ray sources based on resonant backscattering of laser beams with relativistic heavy ion beams

Resonant backscattering of high-power laser beam with non-fully stripped, ultra-relativistic ion beams in storage rings is studied as a source for {gamma}-ray beams for elementary particle physics experiments. The laser frequency is chosen to be resonant with one of the transition frequencies of the moving ions, and the bandwidth is chosen to cover the full Doppler broadening of the ions in the beam. Due to the resonance, the scattering cross section is enhanced by a large factor compared to th… more

Date: April 1, 1995

Creator: Bessonov, E.G. & Kim, Kwang-Je

Item Type: Article

Partner: UNT Libraries Government Documents Department