W.M. Fawley
A5077624124- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Advanced X-ray Imaging Techniques
- Gyrotron and Vacuum Electronics Research
- Laser-Plasma Interactions and Diagnostics
- Magnetic confinement fusion research
- Laser Design and Applications
- Pulsed Power Technology Applications
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Advanced Electron Microscopy Techniques and Applications
- Laser-Matter Interactions and Applications
- Crystallography and Radiation Phenomena
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Electrostatic Discharge in Electronics
- Electromagnetic Simulation and Numerical Methods
- Photonic and Optical Devices
- Neutrino Physics Research
- Particle Detector Development and Performance
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Particle physics theoretical and experimental studies
- Advanced Surface Polishing Techniques
- Advanced Fiber Laser Technologies
SLAC National Accelerator Laboratory
1996-2020
Elettra-Sincrotrone Trieste S.C.p.A.
2010-2019
University of California, Berkeley
1975-2013
Lawrence Livermore National Laboratory
1986-2013
Lawrence Berkeley National Laboratory
2002-2011
University of Nevada, Reno
2009
Ludwig-Maximilians-Universität München
2009
Los Alamos National Security (United States)
2007
Los Alamos National Laboratory
2002-2005
Marshall Medical Center
2004
We have substantially increased the output power and extraction efficiency of a free-electron laser operating at 34.6 GHz by tapering wiggler magnetic field. In exponential-gain regime, exhibited measured gain 34 dB/m. With 50-kW input signal, amplifier saturated in 1.3 m with 180-MW signal. By using taper that brought field end down to 45% its initial (peak) value, we signal 1.0 GW. This corresponds an 34%.
A high-gain, high--extraction-efficiency, linearly polarized free-electron laser amplifier has been operated at 34.6 GHz. At low signal levels, exponential gain of 13.4 dB/m measured. With a 3-=kW input signal, saturation was observed with an 80-MW output and 5% extraction efficiency. The results are in good agreement linear models small levels nonlinear large levels.
We propose the use of an ultrarelativistic electron beam interacting with a few-cycle, intense laser pulse and coherent x rays to produce multi-MW intensity, x-ray pulses approximately 100 attoseconds in duration. Because naturally occurring frequency chirp, these can be further temporally compressed.
FERMI@Elettra comprises two free electron lasers (FELs) that will generate short pulses (τ∼25–200 fs) of highly coherent radiation in the XUV and soft x-ray region. The use external laser seeding together with a harmonic upshift scheme to obtain wavelengths give capability producing high-quality, longitudinally photon pulses. This capability, possibilities temporal synchronization control output polarization, open up new experimental opportunities are not possible currently available FELs....
view Abstract Citations (240) References (13) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The peculiar object HD 44179 ("The red rectangle"). Cohen, M. ; Anderson, C. Cowley, A. Coyne, G. V. Fawley, W. Gull, T. R. Harlan, E. Herbig, H. Holden, F. Hudson, S. Jakoubek, O. Johnson, Merrill, K. Schiffer, Soifer, B. Zuckerman, A strong infrared source detected in the AFCRL sky survey is confirmed, and identified with binary star 44179, embedded a nebula. UBVRI...
FERMI is a seeded free-electron laser (FEL) facility located at the Elettra laboratory in Trieste, Italy, and now user operation with its first FEL line, FEL-1, covering wavelength range between 100 20 nm. The second FEL-2, high-gain harmonic generation double-stage cascade 20-4 nm, has also completed commissioning call been recently opened. An overview of typical operating modes presented.
The FERMI facility in Trieste, Italy, is ideal for generating and measuring light characterized by tunable polarization states the vacuum ultraviolet spectral range. New results reveal a high degree of (>0.9) over 26--55 nanometers.
We describe the status of our effort to realize a first neutrino factory and progress made in understanding problems associated with collection cooling muons towards that end. summarize physics can be done factories as well intense cold beams muons. The potential muon colliders is reviewed, both Higgs Factories compact high energy lepton colliders. timescale research development reviewed latest designs channels including promise ring coolers achieving longitudinal transverse simultaneously....
view Abstract Citations (142) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Potential drops above pulsar polar caps: ultrarelativistic particle acceleration along the curved magnetic field. Scharlemann, E. T. ; Arons, J. Fawley, W. M. The paper calculates of a nonneutral stream charged particles from surface an isolated rotating magnetized neutron star in case where flows open field lines poloidal It is shown that very large electrostatic...
view Abstract Citations (138) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Potential drops above pulsar polar caps: acceleration of nonneutral beams from the stellar surface. Fawley, W. M. ; Arons, J. Scharlemann, E. T. We develop a self-consistent, three-dimensional method for calculation steady-state plasma at surface rotating, magnetized, isolated neutron star. When effects work functions are negligible, there is unique monotonic...
FERMI@Elettra is a free electron-laser (FEL)-based user facility that, after two years of commissioning, started preliminary users' dedicated runs in 2011. At variance with other FEL facilities, has been designed to deliver improved spectral stability and longitudinal coherence. The adopted scheme, which uses an external laser initiate the process, demonstrated be capable generating pulses close Fourier transform limit. We report on first instance wavelength tuning, both narrow large range...
An ultraviolet-laser-ionized channel in low-pressure benzene has been successfully used to guide and focus a 7-kA relativistic electron beam over distances up 4 m. In addition, phase-mix damping of coherent, transverse motion demonstrated. A simple analytical model the equilibrium profile is presented which reasonable agreement with data.
SPARC (acronym of ``Sorgente Pulsata ed Amplificata di Radiazione Coerente'', i.e. Pulsed and Amplified Source Coherent Radiation) is a single pass free-electron laser designed to obtain high gain amplification at radiation wavelength 500 nm. Self-amplified spontaneous emission has been observed driving the amplifier with high-brightness beam linac. We report measurements energy, spectra, exponential gain. Experimental results are compared simulations from several numerical codes.
Energy extraction efficiency of a free electron laser (FEL) can be greatly increased using tapered undulator and self-seeding. However, the rate is limited by various effects that eventually lead to saturation peak intensity power. To better understand these effects, we develop model extending Kroll-Morton-Rosenbluth, one-dimensional theory include physics diffraction, optical guiding, radially resolved particle trapping. The predictions agree well with GENESIS single-frequency numerical...
FERMI is the first user facility based upon an externally seeded free-electron laser (FEL) and was designed to deliver high quality, transversely longitudinally coherent radiation pulses in extreme ultraviolet soft x-ray spectral regimes. The linear accelerator includes a heater control longitudinal microbunching instability, which otherwise expected degrade quality of brightness electron beam sufficiently reduce FEL output intensity brightness. In this paper, we present results...
In recent years significant studies have been initiated on the feasibility of utilizing a portion 3 km S-band accelerator at SLAC to drive short wavelength (4.5−1.5 Å) Linac Coherent Light Source (LCLS), Free-Electron Laser (FEL) operating in Self-Amplified Spontaneous Emission (SASE) regime. Electron beam requirements for single-pass saturation minimal time include: 1) peak current 7 kA range, 2) relative energy spread <0.05%, and 3) transverse emittance, ε [rad-m], approximating...
High-power free electron lasers (FEL's) can be realized using induction linear accelerators as the source of beam. These are currently capable producing intense currents (10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> -10 xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> A) at moderately high energy (1-50 MeV). Experiments a 500 A, 3.3 MeV beam have produced 80 MW radiation 34.6 GHz and in good agreement with theoretical analysis....
The frequency offset of the sideband instability in a free-electron laser (FEL) should depend on (1-${v}_{?}$/${v}_{g}$${)}^{\mathrm{\ensuremath{-}}1}$, where ${v}_{?}$ is average longitudinal velocity electrons and ${v}_{g}$ group electromagnetic waves. We have tested ${v}_{?}$/${v}_{g}$ dependence shift 2-mm, Raman-regime FEL oscillator. A change from 0.93 to 0.98, accomplished by an increase undulator period, resulted measured increasing 6% 40%, approximate agreement with theory.
Simulations of the x-ray free-electron laser (FEL) oscillator are presented that include frequency-dependent Bragg crystal reflectivity and transverse diffraction focusing using two-dimensional FEL code GINGER. A review physics reflectors is made, followed by a discussion its numerical implementation in The simulation results for two-crystal cavity realistic parameters indicate $\ensuremath{\sim}{10}^{9}$ photons nearly Fourier-limited, ps pulse. Compressing electron beam to 100 fs...
We present the experimental demonstration of a method for generating two spectrally and temporally separated pulses by an externally seeded, single-pass free-electron laser operating in extreme-ultraviolet spectral range. Our results, collected on FERMI@Elettra facility confirmed numerical simulations, demonstrate possibility controlling both temporal features generated pulses. A operated this mode becomes suitable light source jitter-free, two-colour pump-probe experiments.