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Simulation Of Beam Induced Plasma For The Mitigation Of Beam Beam Effects
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Book Synopsis Simulation of Beam-induced Plasma for the Mitigation of Beam-beam Effects by :
Download or read book Simulation of Beam-induced Plasma for the Mitigation of Beam-beam Effects written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main challenges in the increase of luminosity of circular colliders is the control of the beam-beam effect. In the process of exploring beam-beam mitigation methods using plasma, we evaluated the possibility of plasma generation via ionization of neutral gas by proton beams, and performed highly resolved simulations of the beam-plasma interaction using SPACE, a 3D electromagnetic particle-in-cell code. The process of plasma generation is modelled using experimentally measured cross-section coefficients and a plasma recombination model that takes into account the presence of neutral gas and beam-induced electromagnetic fields. Numerically simulated plasma oscillations are consistent with theoretical analysis. In the beam-plasma interaction process, high-density neutral gas reduces the mean free path of plasma electrons and their acceleration. A numerical model for the drift speed as a limit of plasma electron velocity was developed. Simulations demonstrate a significant reduction of the beam electric field in the presence of plasma. Preliminary simulations using fully-ionized plasma have also been performed and compared with the case of beam-induced plasma.
Book Synopsis Simulation of Beam-Induced Gas Plasma in High Gradient RF Field for Muon Collider by :
Download or read book Simulation of Beam-Induced Gas Plasma in High Gradient RF Field for Muon Collider written by and published by . This book was released on 2013 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Efficient Modeling of Plasma Wake Field Acceleration Experiments Using Particle-in-cell Methods by : Weiming An
Download or read book Efficient Modeling of Plasma Wake Field Acceleration Experiments Using Particle-in-cell Methods written by Weiming An and published by . This book was released on 2013 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is no clear path for building a particle accelerator at the energy frontier beyond the Large Hadron Collider (LHC). One option that is receiving attention is to use plasma wave wakefields driven by intense particle beams. Recent experiments conducted at the Stanford Linear Accelerator Center (SLAC) show that accelerating gradients in such wakefields in excess of 50 GeV/m can be sustained over meter scales. Based on this, a linear collider concept of staging one-meter long plasma cells together has been proposed. A facility at SLAC has been built to study the physics in one stage. In this dissertation we describe improvements and enhancements to a highly efficient simulation model for simulating current experiments at SLAC as well as parameters beyond the reach of current experiments. The model is the quasi-static particle-in-cell (PIC) code QuickPIC. A modified set of quasi-static field equations were developed, which reduced the number of predictor corrector iteration loops and an improved source deposit scheme was developed to reduce the parallel communication. These improvements led to a factor of 5 to 8 (depending on the simulation parameters) speedup compared with the previous set of field equations and deposition scheme. Several new modules were also added to QuickPIC, including the multiple field ionization and improved beam and plasma particle diagnostics. We also used QuickPIC to study the optimum plasma density for maximizing the acceleration field for fixed electron beam parameters. QuickPIC simulations were also used to study and design two-bunch PWFA experiments at SLAC including methods for mitigating the ionization-induced beam head erosion. The mitigation methods can enhance the energy gain in two-bunch PWFA experiments at SLAC by a factor of 10 for the same beam parameters. For beam parameters beyond SLAC but perhaps necessary for a future collider, QuickPIC was used to study how the ultra high electric fields of a tightly focused second electron bunch could lead to ion motion, which disrupts the focusing fields on the second bunch. The resulting nonlinearity in the transverse focusing force of the plasma wake will lead to emittance growth. We used QuickPIC to carry out the first fully self-consistent high resolution simulation on the effects of ion motion for PWFA linear collider problems. Preliminary results showed that the plasma-ion-motion-induced emittance growth was limited to less than a factor of 2. In addition to the electron beam driven PWFA, we also study how a short proton beam can excite a large plasma wake. Such short proton beams are currently not experimentally available. We therefore also study how long proton beams such as those at Fermi National Laboratory and CERN may drive a large plasma wake through a self-modulation instability. A linear theory for the self-modulation instability is presented under the wide beam limit. QuickPIC simulations show that the self-modulation of a long proton beam in a plasma may lead to the micro-bunching of the beam and excite a large plasma wake.
Book Synopsis Emittance Preservation in a Plasma Wakefield Accelerator by : Yujian Zhao
Download or read book Emittance Preservation in a Plasma Wakefield Accelerator written by Yujian Zhao and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma-based acceleration (PBA) is being considered as the basis for a future linear collider,where electrons and positron bunches must collide with extremely small spot sizes. In order to be focused to such spot sizes the beams must have extremely small emittances. Thus one challenge to a PBA collider is preserving the emittance of the accelerated beams. In this dissertation, the evolution and preservation of the witness beam emittance in aplasma-based accelerator in the nonlinear blowout regime is investigated using theory and particle-in-cell simulations. It it found that the use of plasma density ramps as matching sections are beneficial for emittance emittance growth mitigation and preservation even when the witness beam is focused so tightly within the plasma that its space charge force pulls ions inwards within the beam. In order to study the evolution of a beam in the wakefield, details of the motion ofa single beam particle in the accelerating and focusing fields of a nonlinear wakefield are presented. The exact solution to the transverse equation of motion of a single beam particle under the assumption of adiabatic acceleration is derived. Approximate and thus simpler solutions are provided under the assumptions that plasma density also changes adiabatically. Some important concepts, including the beam's envelope equation, geometric emittance, normalized emittance, single and beam C-S parameters, transport matrices, and matching are reviewed and elaborated upon. Emittance evolution and the importance of matching are discussed in the context of a uniform plasma. Using the approximate solution (WKB solution) of a single particle's motion, analyticalexpressions for the evolution of the beam emittance and the C-S parameters in an arbitrary adiabatic plasma profile are provided neglecting the acceleration of the beam inside the plasma. It is shown that the beam emittance can be preserved when the beams C-S parameters are matched to the entrance of the density profile even when the beam has an initial energy spread. It is also shown that the emittance growth for an unmatched beam is minimized when it is focused to the same vacuum plane as for a matched beam. The emittance evolution without ion motion is studied using 3D particle-in-cell QuickPIC simulation and the results agree well with the theoretical predictions. In some of the proposed experiments for the recently commissioned FACET II facility,the matching condition may not be perfectly satisfied and the wake may not be perfectly symmetric. It is shown that for a given set of beam parameters that are consistent with FACET II capabilities, the emittance growth can still be minimized by choosing the optimal focal plane even when the assumptions of the theory are not satisfied. Additional considerations for FACET II experiments were investigated. The plasma source is a lithium plasma confined by a helium buffer gas. The plasma is formed from field ionization which can lead to a nonlinear focusing force inside the helium buffer gas due to its high ionization potential leading to a nonuniform transverse profile for the plasma. It is found in simulations that for an initial beam emittance of 20 [mu]m, the helium ionization is found to be small and the witness beam's emittance can still be preserved. Emittance evolution for beam and plasma parameters relevant to a single stage of amulti-staged plasma-based linear collider (LC) is investigated. In some plasma-based LC designs the transverse space charge forces for extreme accelerating beam parameters are expected to pull background ions into the beam which can lead to longitudinally varying nonlinear focusing forces and result in emittance growth of the beam. To mitigate this, the use of an adiabatic plasma density ramp as a matching section is proposed and examined using theory and PIC simulations. The witness beam is matched to the low density plasma entrance, where the beam initially has a large matched spot size so the ion motion effects are relatively small. As the beam propagates in the plasma density upramp (downramp), it is adiabatically focused (defocused) and its phase space distribution evolves slowly towards an equilibrium distribution including the effects of the adiabatically changing ion motion. Simulation results from QPAD, a new quasi-3D, quasi-static PIC code, show that within a single acceleration stage, this concept can limit the projected emittance growth to only ∼2% for a 25 GeV, 100 nm emittance witness beam and ∼20% for a 100 GeV, 100 nm emittance witness beam. The trade-off between the adiabaticity of the plasma density ramp and the initial ion motion at the entrance for a given length of the plasma density ramp is also discussed. Additional issues for building a plasma based linear collider are discussed. Preliminaryparticle-in-cell simulation results which examine and illustrate problems like staging, shaped witness beam (for improved beam loading), emittance growth and hosing of a witness beam with an initial offset, ion motion triggered by the driver, and asymmetric witness beams are presented. The implications of these issues on a plasma based linear collider are discussed. Simulation results for witness beams with initial energy of 500 GeV such as would exist in a final stage of a PBA linear collider or an afterburner are presented.
Book Synopsis Design Changes to a Laser-plasma Simulation Code to Permit Twisted Light Studies by : Blaine Armstrong
Download or read book Design Changes to a Laser-plasma Simulation Code to Permit Twisted Light Studies written by Blaine Armstrong and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Schemes to implement laser bandwidth wide enough to mitigate laser-plasma instabilities will be both intrusive and expensive. As an alternate approach, work is presented that investigates the mitigating effects of spatial, rather than temporal, laser beam conditioning on cross-beam energy transfer (CBET) [I.V. Igumenshchev et al., Phys. Plasmas 19, 056314 (2012)]. Such conditioning might be generated by phase plates alone and could therefore be implemented more easily. We have quantified the energy exchange occurring between crossing laser beams that possess orbital angular momentum (OAM) as the amount of OAM exchange between the beams is varied [cf. e.g., M. Padgett et al., Physics Today 57, 35 (2004)]. This work enables studies to be performed in 3-D using the non-paraxial wave-based LPSE simulation code [J.F. Myatt et al., J. Comp. Phys 399, 108916 (2019)]. It required significant modifications to the code to allow for the beams with OAM. The modifications required changes to the boundary conditions and the total field scattered field (TF-SF) to be implemented successfully.
Book Synopsis Study of Electronegative Gas Effect in Beam Induced Plasma by :
Download or read book Study of Electronegative Gas Effect in Beam Induced Plasma written by and published by . This book was released on 2012 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Simulations of the Effects of Mobile Ions on the Relativistic Beam-plasma Instability for Intense Beams by :
Download or read book Simulations of the Effects of Mobile Ions on the Relativistic Beam-plasma Instability for Intense Beams written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Particle-in-cell simulations of the beam-plasma instability for intense relativistic electron beams in dense plasmas show rapid heating of the electrons to multi-kilovolt temperatures. The resulting hydrodynamic motion of the plasma results in density gradients that degrade the interaction. Heat flow out of the plasma is found in some instances to limit the gradient formation process.
Book Synopsis Simulation of Parametric Instability Effects in a Beam Plasma System by :
Download or read book Simulation of Parametric Instability Effects in a Beam Plasma System written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An energetic electron beam produces large amplitude resonant plasma oscillations which can parametrically decay into growing nonresonant electron and ion waves if ion dynamics are included. A similar parametric instability occurs in a plasma driven by a high frequency external electric field. A two-specie particle simulation study of beam generated parametric instabilities is presented and the results compared with corresponding one-specie beam and external field simulations. For low beam densities the individual nonresonant modes grow approximately at the rates predicted by parametric instability theory. This growth eventually causes the resonant plasma oscillations to decay exponentially at a rate proportional to the original parametric growth rate. f/sub e/(v) develops suprathermal tails which eventually lead to a stable non-Maxwellian plasma with a field energy spectrum W/sub k/ approximately k$sup -2$ as seen in external field simulations. The velocity diffusion coefficient has been measured from test particle dynamics, and beam plasmas driven by an external field have been simulated. Also, the possible role of the parametric instability in stabilizing the beam against deceleration has been studied, and the inclusion of parametric threshold effects lead to more stringent requirements for parametric stabilization than had been previously assumed. The consequences for several astrophysical and laboratory plasma systems are discussed.
Book Synopsis Simulation of Parametric Instability Effects in a Beam Plasma System by : Richard F. Hubbard
Download or read book Simulation of Parametric Instability Effects in a Beam Plasma System written by Richard F. Hubbard and published by . This book was released on 1975 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Simulations of the Nuetral-beam-induced Rotation, Radial Electric Field, and Flow Shearing Rate in Next-step Burning Plasmas by : R. V. Budny
Download or read book Simulations of the Nuetral-beam-induced Rotation, Radial Electric Field, and Flow Shearing Rate in Next-step Burning Plasmas written by R. V. Budny and published by . This book was released on 2002 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Halide Perovskites by : Tze-Chien Sum
Download or read book Halide Perovskites written by Tze-Chien Sum and published by John Wiley & Sons. This book was released on 2019-03-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real insight from leading experts in the field into the causes of the unique photovoltaic performance of perovskite solar cells, describing the fundamentals of perovskite materials and device architectures. The authors cover materials research and development, device fabrication and engineering methodologies, as well as current knowledge extending beyond perovskite photovoltaics, such as the novel spin physics and multiferroic properties of this family of materials. Aimed at a better and clearer understanding of the latest developments in the hybrid perovskite field, this is a must-have for material scientists, chemists, physicists and engineers entering or already working in this booming field.
Book Synopsis Particle-in-cell Simulation of a Beam-plasma Discharge by : Ian James Morey
Download or read book Particle-in-cell Simulation of a Beam-plasma Discharge written by Ian James Morey and published by . This book was released on 1986 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling of Plasma Dynamics During Pulsed Electron Beam Ablation of Graphite by : Muddassir Ali
Download or read book Modeling of Plasma Dynamics During Pulsed Electron Beam Ablation of Graphite written by Muddassir Ali and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in the field of plasma nanofabrication suggest that plasma-based technologies may replace many of the conventional chemical and thermal routes in the synthesis of nanomaterials (with at least one dimension below 100 nm) and thin films. In contrast to the conventional processing routes, where only neutral species are involved, a plasma is made up of energetic species including ions, electrons, and excited molecules in addition to neutrals. Due to the highly energetic nature of interactions among these species and with other surfaces (substrates), a plasma allows for the formation of materials at higher rates even though their concentrations might be low as compared with those of neutral species in non-plasma based methods. While the mechanisms of the various interactions in a plasma are undoubtedly complex and require a fundamental understanding, they offer new opportunities for material nanofabrication. Pulsed electron beam ablation (PEBA) has recently emerged as a novel and promising technique for high quality thin films growth. Pulsed electron beam film deposition consists of many physical processes including target material heating, target ablation, plasma plume expansion, and film growth on a substrate. Electron beam ablation is a complex process, which comprises heating, phase change, and removal of a fine fraction from the target surface. Ablation strongly affects the space distribution, composition, mass transfer processes, which in turn has a critical bearing on the structure, stoichiometry and properties of thin films. Plasma plume expansion into an ambient gas is a fundamental issue in PEBA as the quality of thin films deposited onto the substrate depends on the composition, energy and density of particles ejected from the target. A one-dimensional heat conduction model is presented to investigate the heating and ablation of a graphite target upon interaction with a polyenergetic electron beam. The effect of electron beam efficiency, power density, accelerating voltage, and Knudsen layer just above the target surface during ablation are taken into account in the model. Phase transition induced during ablation is considered through the temperature dependent thermodynamic properties of graphite. The temperature distribution, surface receding velocity, melting depth, ablation depth, and ablated mass per unit area are numerically simulated. Upon ablation, plasma expansion, induced by interaction of a nanosecond electron beam pulse (~100 ns) with a graphite target in an argon atmosphere at reduced pressure, was investigated by solving gas-dynamics equations. The spatiotemporal profiles of the temperature, pressure, velocity, and density of the plasma plume are numerically simulated for a beam efficiency of 0.6 and accelerating voltage of 15 kV. Each model is validated by comparing some of the obtained simulation results with experimental data available in the literature.
Book Synopsis Non-Linear Stabilization of Beam Plasma Interactions by Parametric Effects by : K. Papadopoulos
Download or read book Non-Linear Stabilization of Beam Plasma Interactions by Parametric Effects written by K. Papadopoulos and published by . This book was released on 1975 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nonlinear stabilization of the kinetic stage of electron beam plasma instability by parametric effects is investigated. It is found that within a definite range of plasma parameters parametric instabilities induced by the beam generated waves can stabilize the system at a level of wave energy density substantially lower than expected by quasi-linear theory. This occurs because at a certain level of beam generated plasma waves the transfer rate of wave energy outside the spectral region in resonance with the beam induced by parametric effects exceeds the beam plasma instability growth rate. A model of a quasi-steady state for the case of continuous beam injection is proposed. The possibility of using ultra-relativistic electron beams for achieving ignition temperatures in a Tokamak is discussed.
Book Synopsis Computer Simulation of Beam-plasma Interaction by : Barton M. Goldstein
Download or read book Computer Simulation of Beam-plasma Interaction written by Barton M. Goldstein and published by . This book was released on 1977 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Preliminary Considerations Concerning Neutral Plasma Beam Propagation Across a Magnetic Field by :
Download or read book Preliminary Considerations Concerning Neutral Plasma Beam Propagation Across a Magnetic Field written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A plan to address physical questions of interest for exoatmospheric military applications of intense neutralized plasma beams is described. After a brief review of earlier work relevant to this matter and a detailed explanation of why such work cannot answer questions of present interest, a plan employing interactive application of several numerical and analytic techniques to treat relevant phenomena occurring on the various rather disparate time and length scales involved is suggested. The first part of the study would determine the macroscopic features of beam propagation through calculations effected with a magnetohydrodynamical numerical code. Classical transport coefficients would be employed in this initial phase. Using information thus gained concerning gross charge and current distributions, particle-in-cell simulations would be initialized to study those microscopic, phase-space-dependent phenomena which can alter the phenomonological transport coefficients appearing in the fluid description. Insight thereby gained concerning anomaous, collectively induced transport effects would then be applied to yield a refined, accurate description of the macroscopic aspects of neutral plasma beam propagation. Personnel and computational resources available at the Los Alamos Scientific Laboratory are described. Results of a very preliminary particle-in-cell simulation of a neutral plasma beam propagating across a magnetic field are presented.
