Collective Charged Particle Dynamics in Relativistically Transparent Laser-plasma Interactions - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Collective Charged Particle Dynamics in Relativistically Transparent Laser-plasma Interactions write by Bruno González-Izquierdo. This book was released on 2016. Collective Charged Particle Dynamics in Relativistically Transparent Laser-plasma Interactions available in PDF, EPUB and Kindle. 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.
The Physics of Laser Plasmas and Applications - Volume 1
The Physics of Laser Plasmas and Applications - Volume 1 - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook The Physics of Laser Plasmas and Applications - Volume 1 write by Hideaki Takabe. This book was released on 2020-08-28. The Physics of Laser Plasmas and Applications - Volume 1 available in PDF, EPUB and Kindle. The series of books discusses the physics of laser and matter interaction, fluid dynamics of high-temperature and high-density compressible plasma, and kinetic phenomena and particle dynamics in laser-produced plasma. The book (Vol.1) gives the physics of intense-laser absorption in matter and/or plasma in non-relativistic and relativistic laser-intensity regime. In many cases, it is explained with clear images of physics so that an intuitive understanding of individual physics is possible for non-specialists. For intense-laser of 1013-16 W/cm2, the laser energy is mainly absorbed via collisional process, where the oscillation energy is converted to thermal energy by non-adiabatic Coulomb collision with the ions. Collisionless interactions with the collective modes in plasma are also described. The main topics are the interaction of ultra-intense laser and plasma for the intensity near and over 1018W/cm2. In such regime, relativistic dynamics become essential. A new physics appears due to the relativistic effects, such as mass correction, relativistic nonlinear force, chaos physics of particle motions, and so on. The book provides clearly the theoretical base for challenging the laser-plasma interaction physics in the wide range of power lasers. It is suitable as a textbook for upper-undergraduate and graduate students as well as for readers who want to understand the whole physics structure about what happen when an intense-laser irradiates any materials including solids, gas etc. Explaining the physics intuitively without complicated mathematics, it is also a valuable resource for engineering students and researchers as well as for self-study.
High-Power Laser-Plasma Interaction
High-Power Laser-Plasma Interaction - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook High-Power Laser-Plasma Interaction write by C. S. Liu. This book was released on 2019-05-23. High-Power Laser-Plasma Interaction available in PDF, EPUB and Kindle. The field of high-power laser-plasma interaction has grown in the last few decades, with applications ranging from laser-driven fusion and laser acceleration of charged particles to laser ablation of materials. This comprehensive text covers fundamental concepts including electromagnetics and electrostatic waves, parameter instabilities, laser driven fusion,charged particle acceleration and gamma rays. Two important techniques of laser proton interactions including target normal sheath acceleration (TNSA) and radiation pressure acceleration (RPA) are discussed in detail, along with their applications in the field of medicine. An analytical framework is developed for laser beat-wave and wakefield excitation of plasma waves and subsequent acceleration of electrons. The book covers parametric oscillator model and studies the coupling of laser light with collective modes.
Relativistically Intense Laser–Microplasma Interactions
Relativistically Intense Laser–Microplasma Interactions - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Relativistically Intense Laser–Microplasma Interactions write by Tobias Ostermayr. This book was released on 2019-07-16. Relativistically Intense Laser–Microplasma Interactions available in PDF, EPUB and Kindle. 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.
Sub-picosecond Dynamics During Relativistic Laser-plasma Interaction
Sub-picosecond Dynamics During Relativistic Laser-plasma Interaction - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Sub-picosecond Dynamics During Relativistic Laser-plasma Interaction write by Mohammed Almassarani. This book was released on 2024*. Sub-picosecond Dynamics During Relativistic Laser-plasma Interaction available in PDF, EPUB and Kindle. 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.
