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Showing 1 to 20 of 69 for “"Langmuir probe."”.
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Langmuir Probe Instrument Suite for Mesosphere Turbulence Experiment Mission
<p>The Langmuir probe technique is the predominant in-situ plasma diagnostic technique, and is arguably the only measurement technique that is universally own on every sounding rocket investigation. Earth's mesosphere region (80-120 km) is a host of many dynamic phenomena such as the noctilucent …
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RF-compensated Langmuir Probe Diagnostics of Pulsed Plasma Ion Implantation System
… importance while characterising plasma with a Langmuir probe. Eliminating radio-frequency waves from the acquired current-voltage curves in a RF-driven plasma has the most effect toward improving electron temperature measurements in such plasmas. In chapter \ref{chap:Langmuir}, the importance …
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CHARACTERIZATION OF BCl₃, SF₆, and BCl₃/SF₆ PLASMAS USING LANGMUIR PROBE MEASUREMENTS
A Langmuir probe study in BCl3, SF6, and mixtures of BCl3/SF6 capacitively-coupled plasmas is presented. In this study, energy distribution functions, electron temperatures (and average electron energy) and electron, positive ion, and negative ion densities were determined as a function of process …
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Additively Manufactured, Multi-Langmuir Probe Plasma Sensing Device for Use on CubeSats
This thesis presents a Langmuir probe (LP) sensor array for CubeSat ionospheric plasma diagnostics. The ionosphere is a critical layer of Earth's atmosphere consisting entirely of plasma, and reliable in-situ measurements made on satellites orbiting within the ionosphere are necessary for better …
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ELECTROSTATIC (LANGMUIR) PROBE MEASUREMENTS IN RF DRIVEN He, N2, BCl3, AND BCl3/N2 PLASMAS
A Langmuir probe diagnostic system was developed to measure the electron density distribution in BCl3/N2 mixtures to determine if an average electron energy increase might be partially responsible for the previously observed etch rate enhancement of GaAs with nitrogen addition. The system was …
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Langmuir probe measurements of an inductively coupled plasma reactor with arbitrary power supply modulation
Includes bibliographical references (pages 63-65).
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Characterization of a Magnetically Contained Hot Filament Plasma Source with a Wide-Sweeping Langmuir Probe
… to remedy both problems. A wide-range Sweeping Langmuir Probe was developed with a ±35 V sweeping range to fully analyze ion and electron saturation regions in the entire IV curve. A method was derived to estimate the chamber source’s filament temperatures. The new Langmuir probe was integrated …
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Optical spectroscopy and langmuir probe diagnostics of microwave plasma in synthesis of graphene-based nanomaterials
… Raman scattering spectroscopy was used to probe the H<sub>2</sub> molecules in the plasma under various parametric conditions. The rotational temperature of H<sub>2</sub> was found to increase with reactor pressure, plasma generator power, and distance from the deposition surface. At 10 …
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Construction and operation of a Mirror Langmuir Probe diagnostic for the Alcator C-Mod tokamak
Langmuir probe diagnostic systems presently employed on Alcator C-Mod and elsewhere generally suffer from a severe limitation: unless multiple electrode or high-frequency bias techniques are employed, these systems can not resolve the rapid changes in plasma electron temperature, floating potential …
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Langmuir Probe Investigations of Helicon Wave Discharges in Three-Dimensions of a Commercial-Scale Plasma Processing Reactor
Made available in DSpace on 2017-07-06T18:55:40Z (GMT). No. of bitstreams: 3 Norman_Jeffrey_E_MS.pdf: 131280649 bytes, checksum: 8855837adc5e4a5499477d831ae9054d (MD5) Norman_Jeffrey_E_MS_ABS.pdf: 587265 bytes, checksum: 169d41c371af9d5cccc4c7791a7b01b3 (MD5) license.txt: 4813 bytes, checksum: …
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High vacuum system and instrumentation for measuring the derivative of the current-voltage characteristic of a Langmuir probe
… of the current-voltage characteristic of a Langmuir Probe, which is needed to determine the electron speed distribution in rare gases. The theory behind using a lock-in amplifier differentiator to obtain the derivative of the I-V characteristic of a Langmuir Probe is derived and discussed. A …
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Generation and Langmuir probe analysis of a DC glow discharge and the deposition of chromium from a carbonyl precursor
… Diagnostics of a nitrogen DC discharge with Langmuir probes and spectroscopy, and experiments designed to deposit chromium metal from a chromium hexacarbonyl precursor (Cr(C0)6). New diagnostic equipment was designed, tested and implemented to record Langmuir probe data with high resolution …
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Ion flux maps and helicon source efficiency in the VASIMR VX-100 experiment using a moving Langmuir probe array
… design, setup, and application of a moving multi-Langmuir probe array that measured and mapped ion flux and plasma source efficiency in a flowing plasma with large (∼1.5 T) external magnetic fields in the VASIMR (Variable Specific Impulse Magnetoplasma Rocket) VX-100 experiment. The probe …
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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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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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Development of an uncompensated diagnostic for the measurement of phase-resolved characteristics in radio-frequency plasmas
… in this thesis is focused on electrostatic probes, in particular, the Langmuir probe, which is arguably the most common diagnostic in the world of experimental plasma physics. Eventhough the Langmuir probe was invented over 80 years ago and was the first diagnostic tool used for studying …
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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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An investigation of the statistical properties of ion acoustic turbulence
… of the fluctuating potential as detected by a Langmuir probe. Measurements are reported for several pressures in the range of 0.050 to 0.200 torr. At all of the pressures investigated significant deviations from normal statistics are found for a range of discharge currents near the threshold of …
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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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