Download or read book Characteristics of Laser driven Electron Acceleration Invacuum written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of free electrons with intense laser beamsin vacuum is studied using a 3D test particle simulation model thatsolves the relativistic Newton-Lorentz equations of motion inanalytically specified laser fields. Recently, a group of solutions wasfound for very intense laser fields that show interesting and unusualcharacteristics. In particular, it was found that an electron can becaptured within the high-intensity laser region, rather than expelledfrom it, and the captured electron can be accelerated to GeV energieswith acceleration gradients on the order of tens of GeV/cm. Thisphenomenon is termed the capture and acceleration scenario (CAS) and isstudied in detail in this paper. The maximum net energy exchange by theCAS mechanism is found to be approximately proportional to a 2_o, in theregime where a_o>100, where a_o = eE_o/m_ewc is a dimensionlessparameter specifying the magnitude of the laser field. The acceleratedGeV electron bunch is a macro-pulse, with duration equal or less thanthat of the laser pulse, which is composed of many micro-pulses that areperiodic at the laser frequency. The energy spectrum of the CAS electronbunch is presented. The dependence of the energy exchange in the CAS onvarious parameters, e.g., a 2_o (laser intensity), w_o (laser radius atfocus), tao (laser pulse duration), b_o (the impact parameter), andtheta_i (the injection angle with respect to the laser propagationdirection), are explored in detail. A comparison with diverse theoreticalmodels is also presented, including a classical model based on phasevelocities and a quantum model based on nonlinear Comptonscattering.
Download or read book Laser Driven Electron Acceleration in Vacuum Gases and Plasmas written by and published by . This book was released on 1996 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper discusses some of the important issues pertaining to laser acceleration in vacuum, neutral gases and plasmas. The limitations of laser vacuum acceleration as they relate to electron slippage, laser diffraction, material damage and electron aperture effects, are discussed. An inverse Cherenkov laser acceleration configuration is presented in which a laser beam is self guided in a partially ionized gas. Optical self guiding is the result of a balance between the nonlinear self focusing properties of neutral gases and the diffraction effects of ionization. The stability of self guided beams is analyzed and discussed. In addition, aspects of the laser wakefield accelerator are presented and laser driven accelerator experiments are briefly discussed.
Download or read book Laser Wakefield Electron Acceleration written by Karl Schmid and published by Springer Science & Business Media. This book was released on 2011-05-18 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams.
Download or read book Laser driven Electron Acceleration in Infinite Vacuum written by Liang Jie Wong and published by . This book was released on 2011 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: I first review basic models for laser-plasma interaction that explain electron acceleration and beam confinement in plasma. Next, I discuss ponderomotive electron acceleration in infinite vacuum, showing that the transverse scattering angle of the accelerated electron may be kept small with a proper choice of parameters. I then analyze the direct (a.k.a. linear) acceleration of an electron in infinite vacuum by a pulsed radially-polarized laser beam, consequently demonstrating the possibility of accelerating an initially-relativistic electron in vacuum without the use of ponderomotive forces or any optical devices to terminate the laser field. As the Lawson-Woodward theorem has sometimes been cited to discount the possibility of net energy transfer from a laser pulse to a relativistic particle via linear acceleration in unbounded vacuum, I derive an analytical expression (which I verify with numerical simulation results) defining the regime where the Lawson-Woodward theorem in fact allows for this. Finally, I propose a two-color laser-driven direct acceleration scheme in vacuum that can achieve electron acceleration exceeding 90% of the one-color theoretical energy gain limit, over twice of what is possible with a one-color pulsed beam of equal total energy and pulse duration.
Download or read book Proof of principle Experiment for Crossed Laser Beam Electron Acceleration in a Dielectric Loaded Vacuum Structure written by Tomas Plettner and published by . This book was released on 2002 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics Experiment for a Laser Driven Electron Accelerator written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A physics experiment for laser-driven, electron acceleration in a structure loaded vacuum is being carried out at Stanford University. The experiment is to demonstrate the linear dependence of the electron energy gain on the laser field strength. The accelerator structure, made of dielectric, is semi-open, with dimensions a few thousand times the laser wavelength. The electrons traverse the axis of two crossed laser beams to obtain acceleration within a coherence distance. We predict that the demonstration experiment will produce a single-stage, electron energy gain of 300 keV over a 2.5 mm distance. Ultimately, acceleration gradients of 1 GeV/m should be possible.
Download or read book First Observations of Laser Driven Acceleration of Relativistic Electrons in a Semi Infinite Vacuum Space written by J. E. Spencer and published by . This book was released on 2006 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have observed acceleration of relativistic electrons in vacuum driven by a linearly polarized visible laser beam incident on a thin gold-coated reflective boundary. The observed energy modulation effect follows all the characteristics expected for linear acceleration caused by a longitudinal electric field. As predicted by the Lawson-Woodward theorem the laser driven modulation only appears in the presence of the boundary. It shows a linear dependence with the strength of the electric field of the laser beam and also it is critically dependent on the laser polarization. Finally, it appears to follow the expected angular dependence of the inverse transition radiation process. experiment as the Laser Electron Accelerator Project (LEAP).
Download or read book Vacuum Laser Acceleration written by and published by . This book was released on 1995 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this communication is to comment on and discuss laser acceleration of electrons in vacuum. In particular, we will: (1) critique the recent paper by C.M. Haaland, titled "Laser Electron Acceleration in Vacuum," (2) discuss some general features and characteristics of laser acceleration in vacuum, and (3) propose a vacuum laser acceleration concept called the "vacuum beat wave accelerator."
Download or read book Vacuum Electron Acceleration by an Intense Laser written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using 3D test particle simulations, the characteristics and essential conditions under which an electron, in a vacuum laser beam, can undergo a capture and acceleration scenario (CAS). When a0 ≈> 100 the electron can be captured and violently accelerated to energies ≈> 1 GeV, with an acceleration gradient ≈> 10 GeV/cm, where a0 = eE0/m{sub e}[omega]c is the normalized laser field amplitude. The physical mechanism behind the CAS is that diffraction of the focused laser beam leads to a slowing down of the effective wave phase velocity along the captured electron trajectory, such that the electron can be trapped in the acceleration phase of the wave for a longer time and thus gain significant energy from the field.
Download or read book Proof Of Principle Experiment for Laser Driven Acceleration of Relativistic Electrons in a Semi Infinite Vacuum written by and published by . This book was released on 2006 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: We recently achieved the first experimental observation of laser-driven particle acceleration of relativistic electrons from a single Gaussian near-infrared laser beam in a semi-infinite vacuum. This article presents an in-depth account of key aspects of the experiment. An analysis of the transverse and longitudinal forces acting on the electron beam is included. A comparison of the observed data to the acceleration viewed as an inverse transition radiation process is presented. This is followed by a detailed description of the components of the experiment and a discussion of future measurements.
Download or read book Compact Laser driven Electron Acceleration Bunch Compression and Coherent Nonlinear Thomson Scattering written by Liang Jie Wong and published by . This book was released on 2013 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent hard x-rays have many medical, commercial and academic research applications. To facilitate the design of a table-top coherent hard x-ray source, this thesis studies the linear acceleration of electrons by optical lasers in unbounded vacuum, the linear acceleration and compression of electron bunches by coherent terahertz pulses in cylindrical waveguides, and the generation of coherent hard x-ray radiation by nonlinear Thomson scattering of compressed electron bunches. The Lawson-Woodward theorem describes conditions prohibiting net electron acceleration in laser-electron interactions. We point out how the Lawson-Woodward theorem permits net linear acceleration of a relativistic electron in unbounded vacuum and verify this with electrodynamic simulations. By hypothesizing that substantial net linear acceleration is contingent on the field's ability to bring the particle to a relativistic energy in its initial rest frame, we derive a general formula for the acceleration threshold, which is useful as a practical guide to the laser intensities that linear vacuum acceleration requires. We characterize the scaling laws of linear acceleration by a pulsed radially-polarized beam in infinite vacuum, showing that greater energy gain is achievable with tighter focusing and the use of pre-accelerated electrons. We propose a two-color linear acceleration scheme that exploits changes in the interference pattern caused by the Gouy phase shift to achieve over 90% the one-color theoretical gain limit, more than twice the 40% achievable with a one-color paraxial beam. Interested in capitalizing on the larger wavelengths of coherent terahertz radiation to accelerate larger electron bunches, we study electron acceleration and bunch compression in a cylindrical metal-coated dielectric waveguide. We numerically predict an achievable acceleration gradient of about 450 MeV/m using a 20 mJ terahertz pulse, and separately achieve a 50 times compression to a few-femtosecond duration of a 1.6 pC relativistic electron bunch. Finally, we numerically study the production of coherent hard x-rays via nonlinear Thomson scattering for different degrees of laser focusing. We derive an approximate analytical formula for the optimal incident field intensity that maximizes the radiation intensity spectral peak for a given output and input frequency.
Download or read book Proposed Physics Experiments for Laser Driven Electron Linear Acceleration in a Dielectric Loaded Vacuum Final Report written by and published by . This book was released on 2016 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report summarizes the last three years of research on the development of advanced linear electron accelerators that utilize dielectric wave-guide vacuum channels pumped by high energy laser fields to accelerate beams of electrons.
Download or read book Relativistic Electron Mirrors written by Daniel Kiefer and published by Springer. This book was released on 2014-07-25 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dense sheet of electrons accelerated to close to the speed of light can act as a tuneable mirror that can generate bright bursts of laser-like radiation in the short wavelength range simply via the reflection of a counter-propagating laser pulse. This thesis investigates the generation of such a relativistic electron mirror structure in a series of experiments accompanied by computer simulations. It is shown that such relativistic mirror can indeed be created from the interaction of a high-intensity laser pulse with a nanometer-scale, ultrathin foil. The reported work gives a intriguing insight into the complex dynamics of high-intensity laser-nanofoil interactions and constitutes a major step towards the development of a relativistic mirror, which could potentially generate bright burst of X-rays on a micro-scale.
Download or read book Frontiers in High Energy Density Physics written by National Research Council and published by National Academies Press. This book was released on 2003-05-11 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent scientific and technical advances have made it possible to create matter in the laboratory under conditions relevant to astrophysical systems such as supernovae and black holes. These advances will also benefit inertial confinement fusion research and the nation's nuclear weapon's program. The report describes the major research facilities on which such high energy density conditions can be achieved and lists a number of key scientific questions about high energy density physics that can be addressed by this research. Several recommendations are presented that would facilitate the development of a comprehensive strategy for realizing these research opportunities.
Download or read book Opportunities in Intense Ultrafast Lasers written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2018-01-31 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: The laser has revolutionized many areas of science and society, providing bright and versatile light sources that transform the ways we investigate science and enables trillions of dollars of commerce. Now a second laser revolution is underway with pulsed petawatt-class lasers (1 petawatt: 1 million billion watts) that deliver nearly 100 times the total world's power concentrated into a pulse that lasts less than one-trillionth of a second. Such light sources create unique, extreme laboratory conditions that can accelerate and collide intense beams of elementary particles, drive nuclear reactions, heat matter to conditions found in stars, or even create matter out of the empty vacuum. These powerful lasers came largely from U.S. engineering, and the science and technology opportunities they enable were discussed in several previous National Academies' reports. Based on these advances, the principal research funding agencies in Europe and Asia began in the last decade to invest heavily in new facilities that will employ these high-intensity lasers for fundamental and applied science. No similar programs exist in the United States. Opportunities in Intense Ultrafast Lasers assesses the opportunities and recommends a path forward for possible U.S. investments in this area of science.
Download or read book Physics of Laser driven Plasma based Acceleration written by Eric Esarey and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The physics of plasma-based accelerators driven by short-pulse lasers is reviewed. This includes the laser wake-field accelerator, the plasma beat wave accelerator, the self-modulated laser wake-field accelerator, and plasma waves driven by multiple laser pulses. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse direction, electron dephasing, laser pulse energy depletion, as well as beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and plasmas with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Recent experimental results are summarized.
Download or read book First Observation of Laser Driven Particle Acceleration in a Semi Infinite Vacuum Space written by J. E. Spencer and published by . This book was released on 2005 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
