Eric Esarey

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Laser-driven accelerators, in which particles are accelerated by the electric field of a plasma wave (the wakefield) driven by an intense laser, have demonstrated accelerating electric fields of hundreds of GV m(-1) (refs 1-3). These fields are thousands of times greater than those achievable in conventional radio-frequency accelerators, spurring interest(More)
The transverse dynamics of a 28.5-GeV electron beam propagating in a 1.4 m long, (0-2)x10(14) cm(-3) plasma are studied experimentally in the underdense or blowout regime. The transverse component of the wake field excited by the short electron bunch focuses the bunch, which experiences multiple betatron oscillations as the plasma density is increased. The(More)
Unphysical heating and macroparticle trapping that arise in the numerical modeling of laser wakefield accelerators using particle-in-cell codes are investigated. A dark current free laser wakefield accelerator stage, in which no trapping of background plasma electrons into the plasma wave should occur, and a highly nonlinear cavitated wake with(More)
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,(More)
  • E Esarey, P Sprangle, M Pilloff, J Krall
  • 1995
The wave equation describing an ultrashort, tightly focused laser pulse in vacuum is solved analytically. Plasma dispersive effects are also included. Based on exact short-pulse solutions, analytical expressions are obtained for the pulse-length evolution, the pulse centroid motion, and the group velocity. Approximate short-pulse solutions are obtained to(More)
Particle-In-Cell (PIC) codes are often used to study systems where the details of phase-space are important; for example, self trapping or optical injection in laser-plasma accelerators. Here we investigate the numerical heating and macro-particle trajectory errors in 2D PIC simulations of laser-plasma accelerators. The effects of grid resolution and laser(More)
In the E-157 experiment now being conducted at the Stanford Linear Accelerator Center, a 30 GeV electron beam of 2ϫ10 10 electrons in a 0.65-mm-long bunch is propagated through a 1.4-m-long lithium plasma of density up to 2ϫ10 14 e Ϫ /cm 3. The initial beam density is greater than the plasma density, and the head of the bunch expels the plasma electrons(More)
We present results of measurements of spot size and angular divergence of a 30 GeV electron beam though use of optical transition radiation (OTR). The OTR near field pattern and far field distribution are measured as a function of beam spot size and divergence at wavelengths of 441, 532, and 800 nm, for both the single and double foil configurations.(More)
The purpose of this communication is to comment on and discuss laser acceleration of electrons in vacuum. In particular, we will: (i) critique the recent paper by C.M. Haaland [ 11, titled " Laser electron acceleration in vacuum " , (ii) discuss some general features and characteristics of laser acceleration in vacuum and (iii) propose a vacuum laser(More)
Single-cycle terahertz fields generated by coherent transition radiation from a relativistic electron beam are used to study the high field optical response of single crystal GaAs. Large amplitude changes in the sub-band-gap optical absorption are induced and probed dynamically by measuring the absorption of a broad-band optical beam generated by transition(More)