Download or read book Sub picosecond Dynamics During Relativistic Laser plasma Interaction written by Mohammed Almassarani and published by . This book was released on 2024* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, we explore two major themes related to intense laser-matter interaction. Firstly, we present a comprehensive characterization of the intense THz light and charged particle emission from the rear surface of thin targets during the interaction with ultrashort laser pulses. Secondly, we report the first direct visualization of the Coulomb field of relativistic electron bunches from laser-thin solid interactions on a sub-picosecond timescale. We introduce a novel non-destructive single-shot detection scheme based on the electrooptic principle. Our time-resolved measurements reveal a complex temporal structure with multiple electron bunches propagating at nearly the speed of light. Moreover, our observations confirm the contraction of the electric field of the relativistic electron bunches under the Lorentz transformation. Further, we demonstrate the spatiotemporal evolution of the Coulomb field wavefronts as the electron bunches propagate away from the target. This work paves the way for non-invasive measurements of fast dynamics of charged particles on sub-picosecond timescales.
Download or read book Laser to hot electron Conversion Limitations in Relativistic Laser Matter Interactions Due to Multi picosecond Dynamics written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.
Download or read book Relativistic solitary structures inlaser plasma interaction written by Gtz Lehmann and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2009 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of relativistically intense laser radiation with plasma is rich in nonlinear processes like laser pulse self-modulation and self-focusing, wake-field excitation, wave-breaking and the creation of relativistic solitary structures. The creation and evolution of solitary structures during relativistic laser-plasma-interaction is discussed in this book. A relativistic Maxwell-fluid model is formulated to investigate these solitary structures. We discuss the creation of pre-solitons and their transition to post-solitons. The longitudinal and transversal stability of stationary soliton solutions to the Maxwell-fluid model are examined by numerical linear stability analysis. The transversal instability is identified to be the dominant process. Relativistic electrostatic wave-breaking often is part of the nonlinear evolution of unstable relativistic solitons. A process that will eventually lead to wave-breaking for every electrostatic wave in a cold relativistic plasma is presented. The formalism allows a generalization of known criteria to the relativistic regime and to estimate the breaking time.
Download or read book Dynamics of Relativistic Solitary Structures in Laser Plasma Interaction written by Götz Alexander Lehmann and published by . This book was released on 2008 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Laser plasma Interaction in Plasma Channel and Relativistic Particle Dynamics written by Xiaohu Li and published by . This book was released on 2001 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interaction of Intense Subpicosecond Laser Pulses with Underdense Plasmas written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-plasma interactions have been of interest for many years not only from a basic physics standpoint, but also for their relevance to numerous applications. Advances in laser technology in recent years have resulted in compact laser systems capable of generating (psec), 10[sup 16] W/cm[sup 2] laser pulses. These lasers have provided a new regime in which to study laser-plasma interactions, a regime characterized by L[sub plasma][ge] 2L[sub Rayleigh]> c[tau]. The goal of this dissertation is to experimentally characterize the interaction of a short pulse, high intensity laser with an underdense plasma (n[sub o][le] 0.05n[sub cr]). Specifically, the parametric instability known as stimulated Raman scatter (SRS) is investigated to determine its behavior when driven by a short, intense laser pulse. Both the forward Raman scatter instability and backscattered Raman instability are studied. The coupled partial differential equations which describe the growth of SRS are reviewed and solved for typical experimental laser and plasma parameters. This solution shows the growth of the waves (electron plasma and scattered light) generated via stimulated Raman scatter. The dispersion relation is also derived and solved for experimentally accessible parameters. The solution of the dispersion relation is used to predict where (in k-space) and at what frequency (in[omega]-space) the instability will grow. Both the nonrelativistic and relativistic regimes of the instability are considered.
Download or read book Ultrafast Dynamics of Relativistic Laser Plasma Interactions written by Matthew Streeter and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interaction of Intense Subpicosecond Laser Pulses with Underdense Plasmas written by Christine Ann Coverdale and published by . This book was released on 1995 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Picosecond scale Electron Dynamics in Laser produced Plasmas with and Without an External Magnetic Field written by Matthew Warren McCormick and published by . This book was released on 2013 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of ultra-short laser pulses and cluster targets can be used to explore a number of interesting phenomena, ranging from nuclear fusion to astrophysical blast waves. In our experiments, we focused on exploring very fast plasma dynamics of a plasma created by ionizing clusters and monomer gas. By using a 115 fs laser pulse, we can even study sub-picosecond plasma dynamics. In addition, we also wanted to impose an external magnetic field on these plasmas to study how the plasma evolution would change. The results of this work produced two significant results. First, a new, extremely fast ionization mechanism, with velocities as high as 0.5 c, was discovered which allows for significant plasma expansion on a picosecond time-scale. Experimental studies measured the velocity of the ionization wave, while particle-in-cell simulations helped explain the source and longevity of the wave. It was also observed that this ionization wave was not affected by the external magnetic field. Second, the external field was shown to inhibit plasma expansion on a time-scale of tens of picoseconds, which seems to be one of the first demonstrations of magnetic confinement on such a fast time-scale. Simple 1D simulations tell us that the field appears to slow electron heat transport in the plasma as well as inhibiting collisional ionization of electrons expanding into the surrounding gas. The inhibition of plasma expansion by the field on this time-scale may provide some evidence that magnetic confinement of a fusion plasma created by exploding clusters could improve the fusion yield by slowing heat loss as well as possibly electrostatically confining the hot ions.
Download or read book Collective Charged Particle Dynamics in Relativistically Transparent Laser plasma Interactions written by Bruno González-Izquierdo and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports on experimental and numerical investigations of the collective response of electrons and ions to the interaction of ultra-intense (1020 Wcm−2) laser with ultra-thin (nanometre scale) foils undergoing expansion and relativistic induced transparency. The onset of this relativistic mechanism is also characterised and studied in detail. This new insight into relativistic transparency is an important step towards optical control of charged particle dynamics in laser driven dense plasma sources and in its potential applications; including ion and radiation source development.The experimental and numerical investigations exploring the onset and the underpinning physics of the relativistic transparency have focused on its dependency on the target areal density, laser intensity and polarisation. The results show a maximum laser transmission for the thinnest targets investigated, which decreases exponentially with increasing target thickness. The same trend is obtained for linearly and circularly polarised laser light. However, for a given target thickness, the linear polarisation case exhibits a significantly higher transmission fraction, with respect to the circular polarisation case, due to additional electron heating and expansion. Moreover, it is shown that for the thinnest targets, once they become relativistically transparent, the transmitted light fraction increases rapidly as the laser intensity increases. The increasing rate is shown to be more pronounced in the thinnest targets investigated. This is diagnosed by measurement of both the fundamental and second harmonic wavelengths. An alternative approach, based on numerical measurement of the critical surface velocity, as a function of time, for various target thickness, and comparing it with corresponding analytical models is also proposed. The onset of relativistic induced transparency is found to curb the radiation pressure effciency of the charged particle acceleration mechanism.Investigations of the collective response of electrons in ultra-thin foils undergoing transparency show that a 'relativistic plasma aperture' is generated by intense laser light in this regime, resulting in the fundamental optical phenomenon of diffraction. It is numerically found that the plasma electrons collectively respond to the resulting laser near-field diffraction pattern, resulting in a beam of energetic electrons with spatial-intensity distribution, related to this diffraction structure, which can be controlled by variation of the laser pulse parameters,and in turn the onset of relativistic transparency. Additionally, it is shown that static electron beam, and induced magnetic field, structures can be made to rotate at fixed or variable angular frequencies depending on the degree of ellipticity in the laser polarisation. The predicted electron beam distributions using the 'relativistic plasma aperture' concept are verified experimentally.Understanding the collective response of plasma electrons to transparency and how this affects the subsequent acceleration of ions is highly important to the interpretation of experiments exploring ion acceleration employing ultra-thin foils. Control of this collective electron motion, and thus the resultant electrostatic fields, could enable unprecedented control over the spatial-intensity distribution of laser-driven ion acceleration. The results presented in this thesis show that in ultra-thin foils undergoing transparency the electron dynamics are mapped onto the beam of protons accelerated via strong charge-separation-induced electrostatic fields. It is demonstrated that the degree of ellipticity of the laser polarisation defines the spatial-intensity distribution of the proton beam profile and can therefore be used to control it. This demonstration of dynamic optical control of structures within the spatial-intensity distribution of the beam of laser accelerated ions opens a new route to optimising the properties of these promising ion sources.
Download or read book Beschreibung der Feierlichkeiten anl der Durchreise von Herzog Carl August von Sachsen Weimar und Herzogin Luise durch Eisenach nach ihrer Verm hlung 1775 written by and published by . This book was released on 1775 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atoms Solids and Plasmas in Super Intense Laser Fields written by Dimitri Batani and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent developement of high power lasers, delivering femtosecond pulses of 20 2 intensities up to 10 W/cm , has led to the discovery of new phenomena in laser interactions with matter. At these enormous laser intensities, atoms, and molecules are exposed to extreme conditions and new phenomena occur, such as the very rapid multi photon ionization of atomic systems, the emission by these systems of very high order harmonics of the exciting laser light, the Coulomb explosion of molecules, and the acceleration of electrons close to the velocity of light. These phenomena generate new behaviour of bulk matter in intense laser fields, with great potential for wide ranging applications which include the study of ultra-fast processes, the development of high-frequency lasers, and the investigation of the properties of plasmas and condensed matter under extreme conditions of temperature and pressure. In particular, the concept of the "fast ignitor" approach to inertial confinement fusion (ICF) has been proposed, which is based on the separation of the compression and the ignition phases in laser-driven ICF. The aim of this course on "Atom, Solids and Plasmas in Super-Intense Laser fields" was to bring together senior researchers and students in atomic and molecular physics, laser physics, condensed matter and plasma physics, in order to review recent developments in high-intensity laser-matter interactions. The course was held at the Ettore Majorana International Centre for Scientific Culture in Erice from July 8 to July 14,2000.
Download or read book Relativistic Investigations of Laser plasma Interactions and Electrodynamics in a Medium written by Terence Price Rowlands and published by . This book was released on 1996 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Relativistically Intense Laser Microplasma Interactions written by Tobias Ostermayr and published by Springer. This book was released on 2019-07-16 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation covers several important aspects of relativistically intense laser–microplasma interactions and some potential applications. A Paul-trap based target system was developed to provide fully isolated, well defined and well positioned micro-sphere-targets for experiments with focused peta-watt laser pulses. The laser interaction turned such targets into microplasmas, emitting proton beams with kinetic energies exceeding 10 MeV. The proton beam kinetic energy spectrum and spatial distribution were tuned by variation of the acceleration mechanism, reaching from broadly distributed spectra in relatively cold plasma expansions to spectra with relative energy spread as small as 20% in spherical multi-species Coulomb explosions and in directed acceleration processes. Numerical simulations and analytical calculations support these experimental findings and show how microplasmas may be used to engineer laser-driven proton sources. In a second effort, tungsten micro-needle-targets were used at a peta-watt laser to produce few-keV x-rays and 10-MeV-level proton beams simultaneously, both measured to have only few-μm effective source-size. This source was used to demonstrate single-shot simultaneous radiographic imaging with x-rays and protons of biological and technological samples. Finally, the dissertation discusses future perspectives and directions for laser–microplasma interactions including non-spherical target shapes, as well as thoughts on experimental techniques and advanced quantitative image evaluation for the laser driven radiography.
Download or read book Progress in Ultrafast Intense Laser Science written by Antonio Giulietti and published by Springer Science & Business Media. This book was released on 2010-05-21 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume covers a range of topics from this interdisciplinary field, focusing on coherent responses of gaseous and condensed matter to ultrashort intense laser pulses, propagation of intense laser pulses, and laser-plasma interaction and its applications.
Download or read book Laser Physics at Relativistic Intensities written by A.V. Borovsky and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the first time in a book, this monograph describes relativistic and charge-displacement self-channelling, which is the major finding in the physics of superintense laser beams. It also presents general nonlinear models of lasers - plasma interactions specifically in the case of extremely high intensities.
