A5066424062- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Laser-Plasma Interactions and Diagnostics
- Advanced X-ray Imaging Techniques
- Laser Design and Applications
- Pulsed Power Technology Applications
- Advanced Surface Polishing Techniques
- Photocathodes and Microchannel Plates
- Microwave Engineering and Waveguides
- Advanced Electron Microscopy Techniques and Applications
- Photonic and Optical Devices
- Plasma Diagnostics and Applications
- Terahertz technology and applications
- Laser Material Processing Techniques
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- Electron and X-Ray Spectroscopy Techniques
- Laser-induced spectroscopy and plasma
- Atomic and Subatomic Physics Research
- Integrated Circuits and Semiconductor Failure Analysis
- Magnetic confinement fusion research
- High-pressure geophysics and materials
- Planetary Science and Exploration
- Nuclear Physics and Applications
Adaptix (United Kingdom)
2017-2020
University of Electronic Science and Technology of China
2020
University of California, Los Angeles
2007-2017
Stanford University
1996-2013
Manhattanville College
2009-2010
SLAC National Accelerator Laboratory
1996-2010
Istituto Nazionale di Fisica Nucleare
1997-2010
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2005-2010
Brookhaven National Laboratory
2010
University of Southern California
2010
We describe recent advances in the study of particle acceleration using dielectric near-field structures driven by infrared lasers, which we refer to as Dielectric Laser Accelerators. Implications for high energy physics and other applications are discussed.
Self-amplified spontaneous emission in a free-electron laser has been proposed for the generation of very high brightness coherent x-rays. This process involves passing high-energy, high-charge, short-pulse, low-energy-spread, and low-emittance electron beam through periodic magnetic field long series high-quality undulator magnets. The radiation produced grows exponentially intensity until it reaches saturation point. We report on demonstration self-amplified gain, exponential growth, at...
We report experimental observation of narrow-band coherent Cherenkov radiation driven by a subpicosecond electron bunch traveling along the axis hollow cylindrical dielectric-lined waveguide. For an appropriate choice dielectric wall thickness, short-pulse beam current profile excites only fundamental mode structure, producing energetic pulses in terahertz range. present detailed measurements showing narrow emission spectrum peaked at 367 + or - 3 GHz from 1 cm long fused silica capillary...
First measurements of the breakdown threshold in a dielectric subjected to GV/m wakefields produced by short (30-330 fs), 28.5 GeV electron bunches have been made. Fused silica tubes 100 microm inner diameter were exposed range bunch lengths, allowing surface fields up 27 be generated. The onset breakdown, detected through light emission from tube ends, is observed occur when peak electric field at reaches 13.8+/-0.7 GV/m. correlation structure damage beam-induced established using an array...
Advanced high-brightness beam applications such as inverse-Compton scattering (ICS) depend on achieving of ultrasmall spot sizes in high current beams. Modern injectors and compressors enable the production beams having needed short bunch lengths small emittances. Along with these properties comes need to produce tighter foci, using stronger, shorter focal length optics. An approach creating strong focusing systems high-field, small-bore permanent-magnet quadrupoles (PMQs) is reported here....
In this Letter we report on the use of ultrashort infrared laser pulses to generate a copious amount electrons by copper cathode in an rf photoinjector. The charge yield verifies generalized Fowler-Dubridge theory for multiphoton photoemission. emission is verified be prompt using two pulse autocorrelation technique. thermal emittance associated with excess kinetic energy from process comparable one measured frequency tripled uv pulses. high field gun, up 50 pC can extracted 80 fs long,...
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...
Velocity bunching has been recently proposed as a tool for compressing electron beam pulses in modern high brightness photoinjector sources. This is familiar from earlier schemes implemented dc sources, but presents peculiar challenges when applied to current, low emittance beams photoinjectors. The main difficulty foreseen control of oscillations the this scheme, which can be naturally considered an extension compensation process at moderate energies. paper two scenarios velocity bunching,...
Experimental evidence for self-amplified spontaneous emission (SASE) at 530 nm is reported. The measurements were made the low-energy undulator test line facility Advanced Photon Source, Argonne National Laboratory. experimental setup and details of results are presented, as well preliminary analysis. This experiment extends to shorter wavelengths operational knowledge a linac-based SASE free-electron laser explicitly shows predicted exponential growth in intensity optical pulse function...
We report measurements of large gain for a single pass free-electron laser operating in self-amplified spontaneous emission (SASE) at 16 \ensuremath{\mu}m starting from noise. also the first observation and analysis intensity fluctuations SASE radiation high regime. The results are compared with theoretical predictions simulations.
We examine the use of sextupole magnets to correct nonlinearities in longitudinal phase space transformation a relativistic beam charged particles dispersionless translating section, or dogleg. Through heuristic analytical arguments and examples derived from recent experimental efforts, augmented by simulations using particle tracking codes PARMELA ELEGANT, corrections are found be effective optimizing such structures for compression shaping current profile beam, manipulation second-order...
Energy gain of trapped electrons in excess 20 MeV has been demonstrated an inverse-free-electron-laser (IFEL) accelerator experiment. A 14.5 electron beam is copropagated with a 400 GW CO2 laser 50 cm long undulator strongly tapered period and field amplitude. The Rayleigh range the laser, approximately 1.8 cm, much shorter than length yielding diffraction-dominated interaction. Experimental results on dependence acceleration injection energy, focus position, power are discussed....
Recent technological developments have opened the possibility to construct a device which we call linac coherent light source (LCLS) (C. Pellegrini et al., Nucl. Instr. and Meth. A 331 (1993) 223; H. Winick Proc. IEEE 1993 Particle Accelerator Conf., Washington, DC, May 1993; C. Pellegrini, 341 (1994) 326; J. Seeman, SPIE Meet. on Electron Beam Sources of High Brightness Radiation, San Diego, CA, July [1–4]); it would be fourth-generation source, with brightness, coherence, peak power far...
We report the first successful attempt to generate ultrashort (1-10 ps) relativistic electron bunches characterized by a ramped longitudinal current profile that rises linearly from head tail and then falls sharply zero. Bunches with this type of shape may be applied plasma-based accelerator schemes as an optimized drive beam, free-electron lasers means reducing asymmetry in microbunching due slippage. The scheme used employs anisochronous dogleg beam line nonlinear correction elements...
We propose a new type of terahertz (THz) radiation source based on the electron beam-wave interaction. A high-order harmonic-generation process was introduced to traveling-wave tube (TWT)-like device-the high-harmonic TWT or HHTWT. The scheme is configured as frequency multiplier and amplifier with W-band (millimeter wave) input signals THz output power. Simulations show that operation at seventh harmonic possible other order waves were suppressed. can be tuned continuously over 30-GHz...
Traditional tube-based x-ray sources are widely employed in medical imaging, security screening, and industrial inspection. The cone-beam produced by these tubes is simple to apply, but often demands a long stand-off distance the object of interest. When combined with bulk their attendant power supplies cooling systems, footprint requirement traditional impedes use, especially mobile situations. Here we present an approach distributed, flat-panel source, which eliminates aforementioned bulk,...
A new type of folded frame slow-wave structure (SWS) is introduced and used in the design a low-voltage, high-efficiency, widebandwidth millimeter-wave traveling-wave tube (TWT). The high-frequency characteristics structure, including dispersion properties, coupling impedances, reflection are investigated. beam-wave interaction TWT with SWS working at frequency range also calculated using 3-D particle-in-cell algorithms. simulation results reveal that sheet electron beam parameters 6000 V...
Focusing of a 15 MeV electron bunch by plasma lens operated at the threshold underdense regime has been demonstrated. The strong, 1.7 cm focal length, focused both transverse directions simultaneously and reduced minimum area beam spot factor 23. It is shown through analytic analysis simulation that observed spherical aberration this lens, when expressed as fractional departure focusing strength from its linear expectation, ΔK/K=0.08±0.04. This significantly lower than theoretical value for...