Download or read book Laser Produced Plasmas as Drivers of Quasi Parallel Collisionless Shock Formation in the Laboratory written by Peter Ver Bryck Heuer and published by . This book was released on 2020 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quasi-parallel collisionless shocks are objects of considerable interest in space and astrophysics, most notably as possible sites of cosmic ray acceleration. Such shocks occur naturally in systems such as supernova remnants and planetary bow shocks, where the complex and turbulent structures they form are commonly observed by spacecraft. However, \textit{in situ} spacecraft measurements have some inherent limitations, such as a moving reference frame and non-repeatable measurements. Generating a quasi-parallel collisionless shock in a repeatable, well-diagnosed laboratory environment could therefore improve our understanding of their formation and structure. The quasi-parallel collisionless shocks observed in space and astrophysics are far too large to fit in a laboratory, but scaled versions of these systems can be created using smaller, denser plasmas with similar dimensionless parameters. However, quasi-parallel collisionless shocks are particularly challenging to scale to a feasible experiment. The shock formation process is mediated by several electromagnetic ion/ion beam instabilities which require long length scales ($>500$ ion-inertial lengths) to grow, so an experiment must include a long magnetized background plasma. This background plasma must be overlapped over the same length by a highly super-Alfv\'enic beam plasma. Matching the dimensionless parameters of the shocks observed in space sets demanding requirements on the densities of both plasmas as well as the background magnetic field strength. Laser-produced plasmas (LPPs) provide a promising beam plasma source (a ``driver'') for such experiments. A recent experimental campaign has been conducted at UCLA to investigate the potential of LPPs as drivers of quasi-parallel collisionless shocks. These experiments combine one of two high-energy lasers with the magnetized background plasma of the Large Plasma Device (LAPD) to drive the electromagnetic ion/ion beam instabilities responsible for shock formation. The experiments have observed electromagnetic waves consistent with the very early stages of quasi-parallel shock formation. These waves are similar to the ultra-low frequency (ULF) waves observed by spacecraft upstream of the Earth's quasi-parallel bow shock. At present, the amplitudes of the waves generated by these experiments are too low ($dB/B_0 \sim 0.01$) to fully form a quasi-parallel shock. The wave amplitudes observed in these experiments are low because the conditions for beam instability growth are only met in a small region near the laser target. Outside of this region, decreasing LPP density due to velocity dispersion and cross-field transport terminates the wave growth and consequently the shock formation process. Future experiments will require technical innovations to expand this growth region in order to produce larger-amplitude waves. Promising approaches including trains of laser pulses and heating electrons in the background plasma to reduce collisional cross-field transport. Along with comparisons to analytic theory and simulations, the results of the current experiments can inform the design of future laboratory quasi-parallel shock experiments.
Download or read book Generation of Quasi perpendicular Collisionless Shocks by a Laser driven Magnetic Piston written by Derek Schaeffer and published by . This book was released on 2014 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Collisionless shocks are ubiquitous in many space and astrophysical plasmas. However, since space shocks are largely steady-state, spacecraft are not well suited to studying shock formation \textit{in situ}. This work is concerned with the generation and study in a laboratory setting of magnetized, quasi-perpendicular collisionless shocks relevant to space shocks. Experiments performed at the Large Plasma Device (LAPD) at UCLA and the Trident Laser Facility at Los Alamos National Laboratory (LANL) combined a magnetic piston driven by a high-energy laser (Raptor at UCLA or Trident at LANL) incident on a carbon target with a preformed, magnetized background plasma. Magnetic flux measurements and 2D hybrid simulations indicate that a magnetosonic pulse consistent with a low-Mach number collisionless shock was formed in the ambient plasma. The characteristics of the shock are analyzed and compared to other experiments in which no shock or a shock precursor formed. The results and simulations reveal that the various experimental conditions can be organized into weak and moderate coupling regimes, in which no shock forms, and a strong coupling regime, in which a full shock forms. A framework for studying these regimes and designing future shock experiments is devised. Early-time laser-plasma parameters necessary to characterize the different shock coupling regimes are studied through experiments performed at the LAPD and Phoenix laboratory at UCLA. In addition to spectroscopic and fast-gate filtered photography, the experiments utilize a custom Thomson scattering diagnostic, optimized for a novel electron density and temperature regime where the transition from collective to non-collective scattering could be spatially resolved. Data from the experiments and 3D analytic modeling indicate that the laser-plasma is best fit at early times with an isentropic, adiabatic fluid model and is consistent with a recombination-dominated plasma for which the electron temperature $T_e\propto t^{-1}$. In addition, spectroscopic measurements and 1D radiation-MHD simulations reveal that the laser-plasma velocity distribution is segregated by charge state, with the fastest ion species having the highest charge state, but the slowest species having the most mass. The results also suggest that the fastest non-trivial ion population (the dominant charge state) at typical laser intensities (I0 ~ 1011 W cm −2) is CV (C4).
Download or read book Laser Plasma Interactions written by Dino A. Jaroszynski and published by CRC Press. This book was released on 2009-03-27 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Solid Compendium of Advanced Diagnostic and Simulation ToolsExploring the most exciting and topical areas in this field, Laser-Plasma Interactions focuses on the interaction of intense laser radiation with plasma. After discussing the basic theory of the interaction of intense electromagnetic radiation fields with matter, the book covers three ap
Download or read book The Physics of Laser Plasmas and Applications Volume 1 written by Hideaki Takabe and published by Springer Nature. This book was released on 2020-08-28 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Collisionless Shocks in Space Plasmas written by David Burgess and published by Cambridge University Press. This book was released on 2015-07-30 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: An engaging introduction to collisionless shocks in space plasmas, presenting a complete review, from first principles to current research.
Download or read book Collisionless Shock Experiments with Lasers and Observation of Weibel Instabilities written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Astrophysical collisionless shocks are common in the universe, occurring in supernova remnants, gamma ray bursts, and protostellar jets. They appear in colliding plasma flows when the mean free path for ion-ion collisions is much larger than the system size. It is believed that such shocks could be mediated via the electromagnetic Weibel instability in astrophysical environments without preexisting magnetic fields. Here, we present laboratory experiments using high-power lasers and investigate the dynamics of high-Mach-number collisionless shock formation in two interpenetrating plasma streams. Our recent proton-probe experiments on Omega show the characteristic filamentary structures of the Weibel instability that are electromagnetic in nature with an inferred magnetization level as high as ~1% These results imply that electromagnetic instabilities are significant in the interaction of astrophysical conditions.
Download or read book Simulations of Super Alfvenic Laser Ablation Experiments in the Large Plasma Device written by Stephen Eric Clark and published by . This book was released on 2016 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hybrid plasma simulations, consisting of kinetic ions treated using standard Particle- In-Cell (PIC) techniques and an inertialess charge-neutralizing electron fluid, have been used to investigate the properties of collisionless shocks for a number of years. They agree well with sparse data obtained by flying through Earth's bow shock and have been used to model high energy explosions in the ionosphere. In this doctoral dissertation hybrid plasma simulation is used on much smaller scales to model collisionless shocks in a controlled laboratory setting. Initially a two-dimensional hybrid code from Los Alamos National Laboratory was used to find the best experimental parameters for shock formation, and interpret experimental data. It was demonstrated using the hybrid code that the experimental parameters needed to generate a shock in the laboratory are relaxed compared to previous work that was done[1]. It was also shown that stronger shocks can be generated when running into a density gradient. Laboratory experiments at the University of California at Los Angeles using the high energy kJ-class Nd:Glass 1053 nm Raptor laser, and later the low energy yet high repetition rate 25 J Nd:Glass 1053 nm Peening laser have been performed in the Large Plasma Device (LAPD), which have provided some much needed data to benchmark the hybrid simulation method. The LAPD provides a repeatable, quiescent, ambient magnetized plasma to surround the exploding laser produced plasma that is ablated from a High Density Polyethylene (HDPE) target. The plasma density peaks in the machine at n_i O(10^13 cm^ 3), which is sufficiently dense to strongly couple energy and momentum from a laser ablated carbon plasma ejected from the HDPE target into the magnetized ambient plasma. It has been demonstrated that a sub-critical shock is formed in the LAPD using the high energy Raptor laser[2], though the data from this experiment is scant. Hybrid simulation was used as an analysis tool for the shock experiments, but there remained the lingering question as to whether the assumptions made in the model sufficiently capture the relevant ion time scale physics and reproduce the magnetic field structure appropriately. A three-dimensional massively parallel hybrid code package was developed, called fHybrid3D, which was used to reexamine the 2013 data with more realistic laser ablation geometry. The data obtained in the 2015 Peening campaign proved to be useful, even though it did not generate a shock, in that it provided some volumetric data to compare to the 3D hybrid simulation. In addition to the larger magnetic field data sets, an emissive probe designed at UCLA[3] was fielded that could measure plasma potential. This is an important measurement, as previously only magnetic fields were measured on the ablation blow-off axis during the high energy laser experiments. This allows the laboratory experiment to directly validate the use of a simple isotropic electron pressure model close to the target. Though through scaling arguments the Larmor fields are strongest and provide the bulk of the ambient ion acceleration, correctly modeling the radial electric fields in the realm of sub-critical shocks is important for getting the coupling right as at lower Mach numbers. The data collected that is compared to simulation output that was converted to electrostatic potential suggests that the electron pressure model is sufficient for modeling perpendicular shocks in the laboratory.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1989 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1971-04 with total page 1658 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Physics written by Alexander Piel and published by Springer. This book was released on 2017-09-07 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: The enlarged new edition of this textbook provides a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The novel fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a concise description of modern plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple and emphasizes the underlying concepts. The guidelines of plasma physics are illustrated by a host of practical examples, preferentially from plasma diagnostics. There, Langmuir probe methods, laser interferometry, ionospheric sounding, Faraday rotation, and diagnostics of dusty plasmas are discussed. Though primarily addressing students in plasma physics, the book is easily accessible for researchers in neighboring disciplines, such as space science, astrophysics, material science, applied physics, and electrical engineering. This second edition has been thoroughly revised and contains substantially enlarged chapters on plasma diagnostics, dusty plasmas and plasma discharges. Probe techniques have been rearranged into basic theory and a host of practical examples for probe techniques in dc, rf, and space plasmas. New topics in dusty plasmas, such as plasma crystals, Yukawa balls, phase transitions and attractive forces have been adopted. The chapter on plasma discharges now contains a new section on conventional and high-power impulse magnetron sputtering. The recently discovered electrical asymmetry effect in capacitive rf-discharges is described. The text is based on an introductory course to plasma physics and advanced courses in plasma diagnostics, dusty plasmas, and plasma waves, which the author has taught at Kiel University for three decades. The pedagogical approach combines detailed explanations, a large number of illustrative figures, short summaries of the basics at the end of each chapter, and a selection of problems with detailed solutions.
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 Plasma Science written by National Academies of Sciences Engineering and Medicine and published by . This book was released on 2021-02-28 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma Science and Engineering transforms fundamental scientific research into powerful societal applications, from materials processing and healthcare to forecasting space weather. Plasma Science: Enabling Technology, Sustainability, Security and Exploration discusses the importance of plasma research, identifies important grand challenges for the next decade, and makes recommendations on funding and workforce. This publication will help federal agencies, policymakers, and academic leadership understand the importance of plasma research and make informed decisions about plasma science funding, workforce, and research directions.
Download or read book Physics of Collisionless Shocks written by André Balogh and published by Springer Science & Business Media. This book was released on 2013-01-04 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book provides a contemporary systematic treatment of shock waves in high-temperature collisionless plasmas as are encountered in near Earth space and in Astrophysics. It consists of two parts. Part I develops the complete theory of shocks in dilute hot plasmas under the assumption of absence of collisions among the charged particles when the interaction is mediated solely by the self-consistent electromagnetic fields. Such shocks are naturally magnetised implying that the magnetic field plays an important role in their evolution and dynamics. This part treats subcritical shocks which dissipate flow energy by generating anomalous resistance or viscosity. The main emphasis is, however, on super-critical shocks where the anomalous dissipation is insufficient to retard the upstream flow. These shocks, depending on the direction of the upstream magnetic field, are distinguished as quasi-perpendicular and quasi-parallel shocks which exhibit different behaviours, reflecting particles back upstream and generating high electromagnetic wave intensities. Particle acceleration and turbulence at such shocks become possible and important. Part II treats planetary bow shocks and the famous Heliospheric Termination shock as examples of two applications of the theory developed in part I.
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Plasma Physics and Controlled Fusion written by Francis F. Chen and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: TO THE SECOND EDITION In the nine years since this book was first written, rapid progress has been made scientifically in nuclear fusion, space physics, and nonlinear plasma theory. At the same time, the energy shortage on the one hand and the exploration of Jupiter and Saturn on the other have increased the national awareness of the important applications of plasma physics to energy production and to the understanding of our space environment. In magnetic confinement fusion, this period has seen the attainment 13 of a Lawson number nTE of 2 x 10 cm -3 sec in the Alcator tokamaks at MIT; neutral-beam heating of the PL T tokamak at Princeton to KTi = 6. 5 keV; increase of average ß to 3%-5% in tokamaks at Oak Ridge and General Atomic; and the stabilization of mirror-confined plasmas at Livermore, together with injection of ion current to near field-reversal conditions in the 2XIIß device. Invention of the tandem mirror has given magnetic confinement a new and exciting dimension. New ideas have emerged, such as the compact torus, surface-field devices, and the EßT mirror-torus hybrid, and some old ideas, such as the stellarator and the reversed-field pinch, have been revived. Radiofrequency heat ing has become a new star with its promise of dc current drive. Perhaps most importantly, great progress has been made in the understanding of the MHD behavior of toroidal plasmas: tearing modes, magnetic Vll Vlll islands, and disruptions.
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 2001-09-30 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 30th Course of the International School of Quantum Electronics on Atoms, Solids and Plasmas in Super-Intense Laser Fields, held 8-14 July, in Erice, Sicily
Download or read book Plasma Physics Index written by and published by . This book was released on 1973 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt:
