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Showing 1 to 20 of 32 for “"Langmuir probes"”.
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Contaminated Sweeping Langmuir Probes on Sounding Rocket Platforms
<p>Sweeping Langmuir Probes (SLPs) are one of the most commonly used probes on sounding rocket missions. They offer measurements of plasma density, electron temperature, and both relative and absolute payload charging. One of the major implementation challenges, however, is contamination on the …
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Development of planar langmuir probes for supersonic plasma flows
Langmuir probes are a long established tool for the investigation and char- acterization of plasmas. Diagnostic use of planar Langmuir probes in sta- tionary low temperature plasmas is a well understood and long established technique. When the plasma possesses a drift velocity greater than the ion …
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Developing Fixed-Bias Langmuir Probes for Multi-Point Constellation Deployments
… in the early 20th century, electrostatic Langmuir probes have proved invaluable in terrestrial and interplanetary ionospheric sounding applications. When deployed aboard rocket and satellite platforms, these probes yield high-cadence, in-situ measurements of key plasma parameters such as …
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A Study into Data Analysis of Varying Types of Langmuir Probes
<p>Langmuir probes are ubiquitously used for in-situ measurements of plasma parameters. These probes have been placed on many different platforms, including experimental sounding rockets for measurements in mesosphere-lower-thermosphere, and also onboard satellites to obtain data sets over an …
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Batch-microfabricated miniaturized planar arrays of Langmuir probes for reentry plasma diagnostics and nanosatellites
… utilizes planar arrays of batch-fabricated micro Langmuir probes that can be surface-mounted on a reentry vehicle or miniaturized satellite as a sensorial skin to perform time-resolved measurements of the electron temperature and number density of the surrounding plasma sheath. These low-cost, …
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Investigation of the shear layer versus the last closed flux surface on TEXT-upgrade
… and simultaneous data from several Langmuir probes are used to determine the locations of features in the shear layer, specifically the flux surface where Er=0, and of the last closed flux surface (LCFS). This is done for several different magnetic configurations. These results are …
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Plasma-Material Interactions: A Langmuir Probe Analysis of a Cylindrical SiO(2) Deposition System and a Computational Study Using VFTRIM3D
… to the plasma properties gathered using Langmuir probes as well as the gas, pressure, and time recipes used to produce them. It is found in this work that the application of $\rm SiO\sb2$ films onto flexible PET bottles using the fashion explained herein results in a decrease in the gas …
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Development of probes for assessment of ion heat transport and sheath heat flux in the boundary of the Alcator C-Mod Tokamak
… in the Alcator C-Mod boundary plasma. These probes are used to asses issues of heat flux and ion energy transport. Systematic studies with these new tools reveal the following: A comparison of surface thermocouples and Langmuir probes confirms standard sheath heat flux theory in a tokamak for …
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Measurements of divertor target plate conditions and their relationship to scrape-off layer transport
… of high heat flux handling, flush-mounted rail Langmuir probes were designed for the Alcator C-Mod divertor. They were validated and proved to be robust, reliable diagnostics. Main chamber SOL fluctuations and density profiles were observed and found to be strongly correlated with divertor …
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Propulsion mechanisms in a helicon plasma thruster
… including a retarding potential analyzer, mach probes and langmuir probes. These diagnostics are used to measure plasma properties such as electron temperature, plasma density, and ion flow velocities. Thruster performance characteristics are then derived from these measurement results. …
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Investigation of asymmetric plasma blob dynamics
… for some of the behavior. Four arrays of Langmuir probes are placed inside the toroidal chamber to measure plasma density. Data collected is shown to confirm the existence of a plasma blob and is analyzed to extract radial and toroidal information. Radial propagation is compared with a …
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Cubesat Wakes in the Earth’s Ionosphere
… ended its mission. DICE carried two fixed-bias Langmuir probes operating in the ion saturation regime that extended 180_ apart from each other on scissor booms. Since the CubeSat was tumbling without proper attitude control, the plasma density measurements rendered by the probes were …
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Planar Ion Probe for Low-Latitude Ionosphere/Thermosphere Enhancements in Density Cubesat Mission
… fluctuations, both spatially and temporally. Langmuir probes are the oldest and most proven instruments for these in-situ measurements. This thesis enumerates the development of a miniaturized low-noise Langmuir probe intended for a dual CubeSat mission to study equatorial temperature and wind …
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Carbon thin films with enhanced properties from cathodic arc plasmas.
… (FCVA) have been examined using planar and wire Langmuir probes in order to optimize the plasma throughput around the 90� bend. The knowledge of plasma characteristics is then utilized to understand the properties of highly tetrahedral amorphous carbon ( ta-C) films as a function of the ion …
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Studies on the dynamics of limited filaments
… short (~1 meter) plasma filaments. Arrays of Langmuir probes track the path of the plasma particles while the limiters are constructed to generate a uniform vertical electric field along its conductive side and measure the parallel current collected. Agreement is found with the model in a …
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Experimental study of current-driven turbulence during magnetic reconnection
… studied using impedance-matched, high-bandwidth Langmuir probes. Strong, broadband fluctuations, with frequencies extending from near the lower-hybrid frequency [fLH = (fcefci)1=2] to the electron cyclotron frequency fce were found to arise during the reconnection events. Based on frequency and …
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Performance testing and internal probe measurements of a high specific impulse Hall thruster
… outfitted with a series of axially distributed Langmuir probes to determine plasma properties inside the discharge channel. Probe data were taken at discharge voltages between 300-900V. Axial profiles of electron temperature, electron density, and plasma potential were measured and compared to …
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Study of ergodic divertor edge density regimes on the tokamaks Tore Supra and TEXTOR, and sensitivity of tunnel probe electron temperature measurements to a suprathermal electron component
… has been investigated experimentally by means of Langmuir probes. As an important first step in the theoretical interpretation of those experiments, a Hamiltonian field line mapping code, which had been previously developed for the TEXTOR dynamic ergodic divertor, has been adapted to the geometry …
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Characteristics of a Multipole Volume H-Plasma
… of the results were obtained using planar Langmuir probes. To facilitate the use of these, a computer-based control and analysis system was built. Empirical corrections were obtained for both electron screening by a magnetic field and ion sheath expansion, and justified theoretically. An …
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