Download or read book Electron Acceleration in Preformed Plasma Channels with Terawatt CO2 Laser written by and published by . This book was released on 1995 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extended cylindrical plasma channels produced under gas breakdown by axicon-focused laser beams may be used as optical waveguides in laser-driven electron accelerators. Plasma channeling of the laser beams will help to maintain a high acceleration gradient over many Rayleigh lengths. In addition, the rarefied gas density channel produced after the optical gas breakdown, and followed by a plasma column expansion, reduces multiple scattering of the electron beam. A high-power picosecond C02laser operational at the ATF and being further upgraded to the 1 TW level is considered as the source for a plasma channel formation and as the laser accelerator driver. We show how various laser accelerator schemes including beat wave, wake field, and Inverse Cherenkov accelerator benefit from using a channeled short-pulse C02laser as a driver.

Download or read book Relativistically Strong CO2 Laser Driver for Plasma channeled Particle Acceleration written by and published by . This book was released on 1995 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long-wavelength, short-duration laser pulses are desirable for plasma wakefield particle acceleration and plasma waveguiding. The first picosecond terawatt CO2 laser is under development to test laser-driven electron acceleration schemes.

Download or read book Electron Acceleration Mechanisms in the Interaction of Ultrashort Lasers with Underdense Plasmas written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment investigating the production of relativistic electrons from the interaction of ultrashort multi-terawatt laser pulses with an underdense plasma is presented. Electrons were accelerated to tens of MeV and the maximum electron energy increased as the plasma density decreased. Simulations have been performed in order to model the experiment. They show a good agreement with the trends observed in the experiment and the spectra of accelerated electrons could be reproduced successfully. The simulations have been used to study the relative contribution of the different acceleration mechanisms: plasma wave acceleration, direct laser acceleration and stochastic heating. The results show that in low density case (1 percent of the critical density) acceleration by laser is dominant mechanism. The simulations at high density also suggest that direct laser acceleration is more efficient that stochastic heating.

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 Energy Research Abstracts written by and published by . This book was released on 1995 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.

Download or read book Electron Acceleration by Laser Fields in a Gas Technical Progress Report written by and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both the 50-MeV electron accelerator and the short-pulse CO2 laser have become operational, and preliminary tests have already been performed involving electrons and shaped lasers beams inside a gas cell. Theoretical work has been performed on the topic of interaction region synthesis and on FEL-type devices involving a gas medium and no wiggler structures. Appendixes present some of the results.

Download or read book Guiding of Terawatt Laser Pulses in Preformed Plasma Channels written by Sergei Petrovich Nikitin and published by . This book was released on 1998 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Acceleration in Relativistic Plasma Waves Generated by a Single Frequency Short pulse Laser written by and published by . This book was released on 1995 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental evidence for the acceleration of electrons in a relativistic plasma wave generated by Raman forward scattering (SRS-F) of a single-frequency short pulse laser are presented. A 1.053 [mu]m, 600 fsec, 5 TW laser was focused into a gas jet with a peak intensity of 8×1017 W/cm2. At a plasma density of 2×1019 cm−3, 2 MeV electrons were detected and their appearance was correlated with the anti-Stokes laser sideband generated by SRS-F. The results are in good agreement with 2-D PIC simulations. The use of short pulse lasers for making ultra-high gradient accelerators is explored.

Download or read book Studies of Electron Acceleration Mechanisms in Relativistic Laser plasma Interactions written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preformed Transient Gas Channels for Laser Wakefield Particle Acceleration written by and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acceleration of electrons by laser-driven plasma wake fields is limited by the range over which a laser pulse can maintain its intensity. This distance is typically given by the Rayleigh range for the focused laser beam, usually on the order of 0.1 mm to 1 mm. For practical particle acceleration, interaction distances on the order of centimeters are required. Therefore, some means of guiding high intensity laser pulses is necessary. Light intensities on the order of a few times 1017 W/cm2 are required for laser wakefield acceleration schemes using near IR radiation. Gas densities on the order of or greater than 1017 cm−3 are also needed. Laser-atom interaction studies in this density and intensity regime are generally limited by the concomitant problems in beam propagation introduced by the creation of a plasma. In addition to the interaction distance limit imposed by the Rayleigh range, defocusing of the high intensity laser pulse further limits the peak intensity which can be achieved. To solve the problem of beam propagation limitations in laser-plasma wakefield experiments, two potential methods for creating transient propagation channels in gaseous targets are investigated. The first involves creation of a charge-neutral channel in a gas by an initial laser pulse, which then is ionized by a second, ultrashort, high-intensity pulse to create a waveguide. The second method involves the ionization of a gas column by an ultrashort pulse; a transient waveguide is formed by the subsequent expansion of the heated plasma into the neutral gas.

Download or read book Laser Wakefield Electron Acceleration Over 100 MeV Driven by a Femtosecond Terawatt Laser Pulse written by M. Kando and published by . This book was released on 1997 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the International Conference on Lasers written by and published by . This book was released on 1997 with total page 1032 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Pre formed Plasma on the Generation and Transport of Fast Electrons in Relativistic Laser solid Interactions written by Bhooshan S. Paradkar and published by . This book was released on 2012 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis we present the dynamics of relativistic fast electrons produced in the laser-solid interactions at the intensities greater than 1018 W/cm2. In particular, the effects of pre-formed plasma in front of a solid target on the generation and transport of these fast electrons is studied. The presence of such a pre-formed plasma is ubiquitous in almost all the present short pulse high intensity laser-solid interaction experiments. First, the generation of fast electrons in the presence of pre-formed plasma of varying density scale-lengths is studied with the help of Particle In Cell (PIC) simulations. It is shown that the fast electrons energy increases with the increasing pre-formed plasma, consistent with the experimental observations. The possible mechanism of generation of such energetic electrons is studied. It is proposed that the interaction of plasma electrons with the laser in the presence of ambipolar electric field, generated due to the laser heating, can result in the electron acceleration beyond laser ponderomotive energy. The analytical and numerical studies of this heating mechanism are presented. In the second part of thesis, the influence of pre-formed plasma on the fast electrons transport is studied. Especially the physics of refluxing of these fast electrons due to the excitation of electrostatic sheath fields inside the pre-formed plasma is investigated. It is shown that this refluxing is responsible for the `annular ring shaped' copper K[alpha] x-ray emission observed in the recent high intensity laser-solid experiments.

Download or read book Tapered Plasma Channels to Phase lock Accelerating and Focusing Forces in Laser plasma Accelerators written by and published by . This book was released on 2010 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tapered plasma channels are considered for controlling dephasing of a beam with respect to a plasma wave driven by a weakly-relativistic, short-pulse laser. Tapering allows for enhanced energy gain in a single laser plasma accelerator stage. Expressions are derived for the taper, or longitudinal plasma density variation, required to maintain a beam at a constant phase in the longitudinal and/or transverse fields of the plasma wave. In a plasma channel, the phase velocities of the longitudinal and transverse fields differ, and, hence, the required tapering differs. The length over which the tapered plasma density becomes singular is calculated. Linear plasma tapering as well as discontinuous plasma tapering, which moves beams to adjacent plasma wave buckets, are also considered. The energy gain of an accelerated electron in a tapered laser-plasma accelerator is calculated and the laser pulse length to optimize the energy gain is determined.

Download or read book Application of Plasma Waveguides to High Energy Accelerators written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The eventual success of laser-plasma based acceleration schemes for high-energy particle physics will require the focusing and stable guiding of short intense laser pulses in reproducible plasma channels. For this goal to be realized, many scientific issues need to be addressed. These issues include an understanding of the basic physics of, and an exploration of various schemes for, plasma channel formation. In addition, the coupling of intense laser pulses to these channels and the stable propagation of pulses in the channels require study. Finally, new theoretical and computational tools need to be developed to aid in the design and analysis of experiments and future accelerators. Here we propose a 3-year renewal of our combined theoretical and experimental program on the applications of plasma waveguides to high-energy accelerators. During the past grant period we have made a number of significant advances in the science of laser-plasma based acceleration. We pioneered the development of clustered gases as a new highly efficient medium for plasma channel formation. Our contributions here include theoretical and experimental studies of the physics of cluster ionization, heating, explosion, and channel formation. We have demonstrated for the first time the generation of and guiding in a corrugated plasma waveguide. The fine structure demonstrated in these guides is only possible with cluster jet heating by lasers. The corrugated guide is a slow wave structure operable at arbitrarily high laser intensities, allowing direct laser acceleration, a process we have explored in detail with simulations. The development of these guides opens the possibility of direct laser acceleration, a true miniature analogue of the SLAC RF-based accelerator. Our theoretical studies during this period have also contributed to the further development of the simulation codes, Wake and QuickPIC, which can be used for both laser driven and beam driven plasma based acceleration schemes. We will continue our development of advanced simulation tools by modifying the QuickPIC algorithm to allow for the simulation of plasma particle pick-up by the wake fields. We have also performed extensive simulations of plasma slow wave structures for efficient THz generation by guided laser beams or accelerated electron beams. We will pursue experimental studies of direct laser acceleration, and THz generation by two methods, ponderomotive-induced THz polarization, and THz radiation by laser accelerated electron beams. We also plan to study both conventional and corrugated plasma channels using our new 30 TW in our new lab facilities. We will investigate production of very long hydrogen plasma waveguides (5 cm). We will study guiding at increasing power levels through the onset of laser-induced cavitation (bubble regime) to assess the role played by the preformed channel. Experiments in direct acceleration will be performed, using laser plasma wakefields as the electron injector. Finally, we will use 2-colour ionization of gases as a high frequency THz source (

Download or read book Optically Controlled Laser Plasma Electron Acceleration for Compact Ray Sources written by Serge Y. Kalmykov and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book COUNTER PROPAGATION OF ELECTRON AND CO2 LASER BEAMS IN A PLASMA CHANNEL written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high-energy CO2 laser is channeled in a capillary discharge. Occurrence of guiding conditions at a relatively low plasma density (