Download or read book Pulsed Plasma Plume Studies written by William J. Guman and published by . This book was released on 1977 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exhaust plume of a millipound thrust level pulsed plasma thruster was studied in a vacuum chamber having all walls cooled by liquid nitrogen. This thruster has a propulsive performance capable of meeting North-South station-keeping requirements of satellites. The major source of contamination of a surface located in the facility was identified to be mainly due to mass being scattered off the walls of the test facility because the walls were incapable of absorbing the highly energetic plume of the first encounter with the wall. By means of a Langmuir probe, calorimetric discs, a collimated QCM and collimated glass capture cups it was found that the transient plume is fairly well collimated and that the outer extremities of the plume are located within + or - 30 degrees to + or - 40 degrees with respect to the geometric center line of the thruster that was studied. Whether or not major changes of the exhaust cone would change this location was not examined. Time resolved studies of the plume by a Langmuir probe and a photocell has shown the life of the plume at a region in space to be only a few tens of microseconds. This result reveals that a spacecraft surface exposed over a 5 to 7 year period to the plume of a North-South station keeping thruster will actually see an accumulated plume flow time for only about 5 minutes during that mission time.
Download or read book Experimental and Theoretical Analysis of Pulsed Plasma Exhaust Plumes written by Dominic J. Palumbo and published by . This book was released on 1978 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pulsed plasma plume diagnostic studies performed in the past have shown that considerable uncertainty exists because of the degree of backscatter encountered in ground test facilities. The large level of backscatter is attributable to the extremely high mass expulsion rate characteristic of solid propellant pulsed plasma thrusters (30 to 40 g/s on the average). The study reported upon herein had the objective of obtaining a suitable analytic model and computational scheme for calculation of the plume characteristics of a 23 mN-s pulsed plasma thruster. The calculated results were compared to experimental measurements of electron number density and temperature, obtained using specially designed Langmuir probes, only up to the point in the time when backscatter of plume effluents off the vacuum chamber walls became significant. A secondary objective of the program was to design a suitable driver circuit for the Langmuir Sangmuir probes so that a voltage ramp could be pulsed for one microsecond at any given time subsequent to thruster discharge initiation and the volt-ampere characteristic could be displayed on an XY oscilloscope.
Download or read book Pulsed Plasma Thruster Plume Study Symmetry and Impact on Spacecraft Surfaces written by Lynn A. Arrington and published by . This book was released on 2000 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High order Harmonic Generation in Laser Plasma Plumes written by Rashid A. Ganeev and published by World Scientific. This book was released on 2013 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents the first comprehensive treatment of high-order harmonic generation in laser-produced plumes, covering the principles, past and present experimental status and important applications. It shows how this method of frequency conversion of laser radiation towards the extreme ultraviolet range matured over the course of multiple studies and demonstrated new approaches in the generation of strong coherent short-wavelength radiation for various applications. Significant discoveries and pioneering contributions of researchers in this field carried out in various laser scientific centers worldwide are included in this first attempt to describe the important findings in this area of nonlinear spectroscopy. High-Order Harmonic Generation in Laser Plasma Plumes is a self-contained and unified review of the most recent achievements in the field, such as the application of clusters (fullerenes, nanoparticles, nanotubes) for efficient harmonic generation of ultrashort laser pulses in cluster-containing plumes and resonance-induced enhancement of harmonic yield. It can be used as an advanced monograph for researchers and graduate students working in the field of nonlinear spectroscopy. It is also suitable for researchers in laser physics and nonlinear optics who wish to have an overview of the advanced achievements in laser ablation-induced high-order harmonic generation spectroscopy. The carefully presented details of this book will be of value to research devoted to the understanding and control frequency conversion of laser pulses in plasma plumes. The studies described in this book pave the way for the development of a new method of materials studies using the laser ablation-induced high-order harmonic generation spectroscopy, which can exploit the spectral and structural properties of various solid-state materials through their ablation and further propagation of short laser pulse through laser-produced plasma and generation of high-order harmonics.
Download or read book Liquid Pulsed Plasma Thruster Plasma Plume Investigation and MR SAT Cold Gas Propulsion System Performance Analysis written by Jeremiah Daniel Hanna and published by . This book was released on 2017 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The plasma plume produced by a liquid pulsed plasma thruster is investigated using a Langmuir triple probe and a nude Faraday probe. The Langmuir triple probe failed to produce results which are suspected caused by the presence of ionic liquid in the plume resulting in shorting of the probe. The nude Faraday probe is able to record the ion current density which revealed a high level of inconsistency in the plasma plume. Ion current density recorded by the nude Faraday probe had a relative standard deviation of upwards of 100% of the mean value. Controlling the amount of propellant used during each pulse was extremely difficult. Investigating the plasma plume with more complex probes was not done due to the inconsistency measured by the nude Faraday probe and the expulsion of ionic liquid from the thruster which is highly corrosive to metals. Examining the historical thrust test data performed by the Missouri Satellite Research Team, a revised model with new assumptions was created and resulted in an improvement in accuracy to within 4.5%. The cold gas propulsion system developed over the years had undergone testing which resulted in measured thrust half of what was predicted. Developing a thrust prediction scheme that incorporates the effects of the solenoid control valve decreases the error to between 1-3% depending on temperature considerations. This thrust prediction scheme can be applied to the current design for the NanoSat 8 competition and results in an accurate prediction of thrust"--Abstract, page iii.
Download or read book Pulsed Laser Ablation of Solids written by Mihai Stafe and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book introduces ‘the state of the art' of pulsed laser ablation and its applications. It is based on recent theoretical and experimental studies. The book reaches from the basics to advanced topics of pulsed laser ablation. Theoretical and experimental fundamental phenomena involved in pulsed laser ablation are discussed with respect to material properties, laser wavelength, fluence and intensity regime of the light absorbed linearly or non-linearly in the target material. The energy absorbed by the electrons leads to atom/molecule excitation, ionization and/or direct chemical bond breaking and is also transferred to the lattice leading to material heating and phase transitions. Experimental non-invasive optical methods for analyzing these phenomena in real time are described. Theoretical models for pulsed laser ablation and phase transitions induced by laser beams and laser-vapour/plasma interaction during the plume expansion above the target are also presented. Calculations of the ablation speed and dimensions of the ablated micro- and nano-structures are performed. The validity and required refinement of different models in different experimental conditions is provided. The pulsed laser deposition process which bases on collecting the ablated particles on a surface is analyzed in terms of efficiency and quality of the deposited films as a function of ambient conditions, target material, laser parameters and substrate characteristics. The interaction between the incident laser and the ablation plasma is analyzed with respect to its influence on the structures of the deposited films and its capacity to generate high harmonics and single attosecond pulses which are highly desirable in pump-probe experiments.
Download or read book High order Harmonic Generation in Laser Plasma Plumes written by Rashid A. Ganeev and published by World Scientific. This book was released on 2013 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents the first comprehensive treatment of high-order harmonic generation in laser-produced plumes, covering the principles, past and present experimental status and important applications. It shows how this method of frequency conversion of laser radiation towards the extreme ultraviolet range matured over the course of multiple studies and demonstrated new approaches in the generation of strong coherent short-wavelength radiation for various applications. Significant discoveries and pioneering contributions of researchers in this field carried out in various laser scientific centers worldwide are included in this first attempt to describe the important findings in this area of nonlinear spectroscopy.High-Order Harmonic Generation in Laser Plasma Plumes is a self-contained and unified review of the most recent achievements in the field, such as the application of clusters (fullerenes, nanoparticles, nanotubes) for efficient harmonic generation of ultrashort laser pulses in cluster-containing plumes and resonance-induced enhancement of harmonic yield. It can be used as an advanced monograph for researchers and graduate students working in the field of nonlinear spectroscopy. It is also suitable for researchers in laser physics and nonlinear optics who wish to have an overview of the advanced achievements in laser ablation-induced high-order harmonic generation spectroscopy. The carefully presented details of this book will be of value to research devoted to the understanding and control frequency conversion of laser pulses in plasma plumes.The studies described in this book pave the way for the development of a new method of materials studies using the laser ablation-induced high-order harmonic generation spectroscopy, which can exploit the spectral and structural properties of various solid-state materials through their ablation and further propagation of short laser pulse through laser-produced plasma and generation of high-order harmonics.
Download or read book Kinetic and Hydrodynamic Simulations of Laser Ablation and Plasma Plume Expansion Induced by Bursts of Short Laser Pulses written by Omid A. Ranjbar and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ablation of materials by nanosecond laser pulses involves expansion of a laser-induced vapor plume into a background gas. The absorption of the incident laser radiation by the plume can substantially decrease the amount of laser energy absorbed directly by the target, and, correspondingly, the amount of the ablated material. This plasma shielding effect limits the overall efficiency of industrial laser systems designed for material removal applications. The goal of the present work is to numerically study the expansion process of plumes induced by irradiation of a metal target by bursts or groups of nanosecond laser pulses and to reveal the implications of the interaction between plumes induced by individual pulses for the efficiency of material removal. The plume expansion induced by irradiation of a copper target in argon background gas is studied based on one- and two-dimensional hybrid computational models that include a hydrodynamic or kinetic model of plasma plumes. The hydrodynamic model is based on finite-difference solution of gas dynamics equations. The kinetic model is implemented in the form of the direct simulation Monte Carlo (DSMC) method. In this work, the generalization of the DSMC method for plasma flows is developed. The effects of laser fluence, spot size, inter-pulse separation, and background gas pressure are thoroughly studied. The numerical simulations of plume expansion induced by a burst of pulses indicate the formation of complicated flow structures with cascades of the primary and secondary shock waves and strong interaction between plumes induced by individual pulses. The simulations reveal the plume accumulation effect when the plumes induced by preceding pulses in a burst change conditions of propagation of plumes generated by subsequent pulses. The degree of plasma shielding increases with increasing number of laser pulses due to the plume accumulation effect. It results in reduction of the effectiveness of material removal by the subsequent pulses. The degrees of the plasma shielding and plume accumulation effects strongly depend on the inter-pulse separation and laser spot size. The trade-off between the plume accumulation and thermal accumulation effects maximizes the ablation depth per pulse at a certain value of the time delay between pulses.
Download or read book Particle Simulation of Pulsed Plasma Thruster Plumes written by and published by . This book was released on 2002 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final report summarizes the research carried out on the development of numerical approaches for simulating the plumes of pulsed plasma thrusters. A significant amount of progress has been made in the three years of this grant and this summarized in the 9 journals and conference papers that are included as appendices to this report. Our modeling had made progress in al aspects of simulating these complex devices including Teflon ablation, plasma formation, electro-magnetic acceleration, plume expansion, and particulate transport. Several different pulsed plasma thruster devices were modeled including an electro-thermal device (the PPT-4 developed at the University of Illinois by Dr. Rod Burton), and various micro-PPT's (developed at the Air Force Research Laboratory by Dr. Greg Spanjers and colleagues).
Download or read book Electromagnetic Effects in the Near Field Plume Exhaust of a Micro Pulsed Plasma Thruster written by and published by . This book was released on 2002 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work we present a model of the near field plasma plume of a Pulsed Plasma Thruster (PPT). As a working example we consider a micro-PPT developed at the Air Force Research Laboratory. This is a miniaturized design of the axisymmetric PPT with a thrust in the 10 micro-N range that utilizes Teflon(Trademark(sup Trademark)) as a propellant. The plasma plume is simulated using a hybrid fluid-PIC-DSMC approach. The plasma plume model is combined with Teflon(Trademark) ablation and plasma generation models that provide boundary conditions for the plume. This approach provides a consistent description of the plasma flow from the surface into the near plume. The magnetic field diffusion into the plume region is also considered and plasma acceleration by the electromagnetic mechanism is studied. Teflon(Trademark) ablation and plasma generation analyses show that file Teflon(Trademark) surface temperature and plasma parameters are strongly non-uniform in the radial direction. The plasma density near the propellant surface peaks at about 10(exp 24)/cu m in the middle of the propellant face while the electron temperature peaks at about 4 eV near the electrodes. The plume simulation shows that a dense plasma focus is developed at a few millimeters from the thruster exit plane at the axis. This plasma focus exists during the entire pulse, but the plasma density in the focus decreases from about 2x10(exp 22)/cu m at the beginning of the pulse down to 0.3x10(exp 22)/cu m at 5 microsec. The velocity phase is centered at about 20 km/s in the axial direction. At later stages of the pulse there are two ion populations with positive and negative radial velocity. Electron densities predicted by file plume model are compared with near field measurements using a Herriot Cell technique and very good agreement is obtained.
Download or read book Numerical Investigations of 2 D Magnetic Nozzles on Pulsed Plasma Plumes written by Joshua Daniel Burch and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This research presents studies of a novel type of magnetic nozzle that allows for three-dimensional (3-D) steering of a plasma plume. Numerical simulations were performed using Tech-X's USim® software to quantify the nozzle's capabilities. A2-D planar magnetic nozzle was applied to plumes of a nominal pulsed inductive plasma (PIP) source with discharge parameters similar to those of Missouri S&T's Missouri Plasmoid Experiment (MPX). Argon and xenon plumes were considered. Simulations were verified and validated through a mesh convergence study as well as comparison with available experimental data. Periodicity was achieved over the simulation run time and phase angle samples were taken to examine plume evolution over pulse cycles. The resulting pressure, velocity, and density fields were analyzed for nozzle angles from 0° to 14°. It was found that actual plume divergence was small compared to the nozzle angle. Even with an offset angle of 14° for the magnetic nozzle, the plume vector angle was only about 2° for argon and less than 1° for xenon. The parameters that had the most effect on the vectoring angle were found to be the coil current and inlet velocity"--Abstract, page iii.
Download or read book Pulsed Laser Deposition of Thin Films written by Robert Eason and published by John Wiley & Sons. This book was released on 2007-12-14 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by major contributors to the field, this text summarizes current or newly emerging pulsed laser deposition application areas. It spans the field of optical devices, electronic materials, sensors and actuators, biomaterials, and organic polymers. Every scientist, technologist and development engineer who has a need to grow and pattern, to apply and use thin film materials will regard this book as a must-have resource.
Download or read book Resonance Enhancement in Laser Produced Plasmas written by Rashid A. Ganeev and published by John Wiley & Sons. This book was released on 2018-07-23 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive guide to a new technology for enabling high-performance spectroscopy and laser sources Resonance Enhancement in Laser-Produced Plasmas offers a guide to the most recent findings in the newly emerged field of resonance-enhanced high-order harmonic generation using the laser pulses propagating through the narrow and extended laser-produced plasma plumes. The author—a noted expert in the field—presents an introduction and the theory that underpin the roles of resonances in harmonic generation. The book also contains a review of the most advanced methods of plasma harmonics generation at the conditions of coincidence of some harmonics, autoionizing states, and some ionic transitions possessing strong oscillator strengths. Comprehensive in scope, this text clearly demonstrates the importance of resonance-enhanced nonlinear optical effects leading to formation of efficient sources of coherent extreme ultraviolet radiation that can be practically applied. This important resource: Puts the focuses on novel applications of laser-plasma physics, such as the development of ultrashort-wavelength coherent light sources Details both the theoretical and experimental aspects of higher-order harmonic generation in laser-produced plasmas Contains information on early studies of resonance enhancement of harmonics in metal-ablated plasmas Analyzes the drawbacks of different theories of resonant high order harmonic generation Includes a discussion of the quasi-phase-matching and properties of semiconductor plasmas Written for researchers and students in the fields of physics, materials science, and electrical engineering who are interested in laser physics and optics, Resonance Enhancement in Laser-Produced Plasmas offers an introduction to the topic and covers recent experimental studies of various resonance processes in plasmas leading to enhancement of single harmonic.
Download or read book Experimental and Theoretical Studies on the Dynamics of Transient Plasma Plumes Generated by Laser Ablation in Various Temporal Regimes written by Stefan-Andrei Irimiciuc and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser ablation methods exhibit a fast development in various application fields, as materials processing, medicine, nuclear fusion or analytical sciences. Despite important advances in the knowledge of the complex laser-matter interactions involved in this process, there is still need for better fundamental understanding and modeling. The aim of this work was to experimentally and theoretically investigate the dynamics of transient plasmas generated by laser ablation in various regimes (ns, ps, fs), and to try to correlate the observed behavior with the physical properties of the ablated materials We implemented space- and time-resolved optical, spectroscopic and electrical methods for the study of single-component metallic targets and of complex chalcogenide targets. This led to a space-time mapping of the main plasma parameters. The study performed in actual Pulsed Laser Deposition (PLD) conditions revealed some peculiar effects like ionic oscillations or plume reflection at the substrate. A compact fractal hydrodynamic model was developed to simulate the laser-produced plasma dynamics. The theoretical model accurately describes the spatial and temporal evolution of the main plasma parameters (electronic temperature, expansion velocities, particle number density, Debye length, plasma potential). We report for the first time empirical relations connecting these plasma parameters with the physical properties (electrical/thermal conductivity, atomic mass, heat of vaporization) of the target. These relationships transcend all three ablation regimes (ns, ps, fs).
Download or read book Laser Ablation written by Tatiana Itina and published by BoD – Books on Demand. This book was released on 2017-12-21 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shortly after the demonstration of the first laser, the most intensely studied theoretical topics dealt with laser-matter interactions. Many experiments were undertaken to clarify the major ablation mechanisms. At the same time, numerous theoretical studies, both analytical and numerical, were proposed to describe these interactions. These studies paved the ways toward the development of numerous laser applications, ranging from laser micro- and nanomachining to material analysis, nanoparticle and nanostructure formation, thin-film deposition, etc. Recently, more and more promising novel fields of laser applications have appeared, including biomedicine, catalysis, photovoltaic cells, etc. This book intends to provide the reader with a comprehensive overview of the current state of the art in laser ablation, from its fundamental mechanisms to novel applications.
Download or read book Advances in Laser Produced Plasmas Research written by Maricel Agop and published by MDPI. This book was released on 2021-01-21 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world of laser matter interaction has known great and rapid advancements in the last few years, with a considerable increase in the number of both experimental and theoretical studies. The classical paradigm used to describe the dynamics of laser produced plasmas has been challenged by new peculiar phenomena observed experimentally, like plasma particles’ oscillations, plume splitting and self-structuring behavior during the expansion of the ejected particles. The use of multiple complementary techniques has become a requirement nowadays, as different aspects can be showcased by specific experimental approaches. To balance these non-linear effects and still remain tributary to the classical theoretical, views on laser produced plasma dynamics novel theoretical models that cover the two sides of the ablation plasma (differentiability and non-differentiability) still need to be developed. Plasma is a strongly nonlinear dynamic system, with many degrees of freedom and other symmetries, favorable for the development of ordered structures, instabilities and transitions (from ordered to chaotic states). In such contexts, we showcased research based on global and local symmetries, complexity and invariance. This special number highlighted exciting new phenomena related to laser produced plasma dynamics with the implementation of theoretical models, towards understanding the complex reality of laser matter interaction.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
