The University of Michigan
Department of Aerospace Engineering
| Plasmadynamics & Electric Propulsion Laboratory |
PEPL Plasma Diagnostics
Langmuir Probe
An electrostatic probe comprised of an exposed electrode that is used to measure plasma electron temperature, electron & ion densities, electron energy distributions, plasma potential, floating potential, and ion beam energy. [view more diagnostic details...]
Flush-mounted Wall Probe
Electrostatic planar Langmuir probes are flush-mounted to the inner and outer discharge channel walls to enable measurements otherwise unobtainable with rapidly inserted probes or laser diagnostics. [view more project/diagnostic details...]
High-speed Dual Langmuir Probe
A unique type of Langmuir probe, originally developed at PEPL in 2008, that employs a compensation or "null" electrode to compensate the active Langmuir probe thereby enabling swept-probe rates of plasma property acquisition in excess of 1 MHz. [view more diagnostic details...]
High-speed Axial Reciprocating Probe
A linear electromagnetic rapid positioning system for <100-ms insertion and removal of probes for internal thruster measurements. [view more diagnostic details...]
High-speed Imaging
Fast shutter (down to <400 ns) continous CMOS high-resolution single-photon sensitive imaging with back-to-back frame rates up to 1 million-frames/s with wide, telephoto, and microscopic optics from 18 mm to >400 mm. [view more diagnostic details...]
Laser Diagnostics
Ongoing research with non-intrusive laser diagnostics includes LIF (laser-induced fluorescence) and laser-doppler velocimetry. New techniques under development at PEPL include CRDS (cavity ring down spectroscopy, for real-time erosion measurements) and time-resolved LIF. [view more project/diagnostic details...]
Inverted Pendulum Thrust Stand
A device that employs an electromagnetically stabilized platform upon which thrusters are operated thereby enabling a direct measurement of thrust typically accurate to ±1 mN. [view more diagnostic details...]
Retarding Potential Analyzer
An electrostatic probe that uses a series of grids to measure the ion energy distribution. [view more diagnostic details...]
ExB Probe
An electrostatic probe that employs perpendicular applied electric and magnetic fields to determine ion charge state. [view more diagnostic details...]
Faraday Probe
An electrostatic probe comprised of an exposed electrode (often guarded) that is used to measure thruster beam current density. [view more diagnostic details...]
Emissive Probe
An electrostatic probe comprised of an exposed electrode that is electrically heated into electron emission thereby floating to the local plasma potential voltage which can then be measured directly. [view more diagnostic details...]
B-dot Probe
A series of loops placed within a time-varying magnetic field that produce a voltage which is directly proportional to dB/dt ("B-dot"). [view more diagnostic details...]
Top Hat Electric Propulsion Plume Analyzer (TOPAZ)
An electrostatic probe that determines the energy, mass, and angular distributions of ions in the far-field plume. [view more diagnostic details...]
Neutral Particle Flux Probe
A small vessel with an ionization pressure gauge that open to ambient plasma conditions through a series of grids that repel all ions and all electrons thereby allowing for a measurement of the neutral particle pressure. [view more diagnostic details...]
Microwave Interferometer
A non-intrusive method of measuring electron density using microwave transmission through a column of plasma. [view more diagnostic details...]
Hall Probe
A Hall probe uses the Hall effect to measure steady (as well as unsteady) magnetic fields. Often used to verify the designed channel magnetic field strength of constructed thrusters. [view more diagnostic details...]
Heat Flux Probe
Measures heat transfer to a surface in a plasma flow. [view more diagnostic details...]
Electron Beam Gun
Measures electric fields, heavy particle velocities and electron collision cross-sections. [view more diagnostic details...]
Parallel-Plate Energy Analyzer
An electrostatic diagnostic that determines ion energy distribution and examines ion energy properties. [view more diagnostic details...]
Time of Flight Mass Spectrometer
Performs species identification and determines fraction of multiply charged ions. [view more diagnostic details...]
Emission Spectroscopy
A non-intrusive diagnostic that measures the relative population and temperature of species. [view more diagnostic details...]
Molecular Beam Mass Spectrometer
Examines ion energy properties and species identification. [view more diagnostic details...]
Electrostatic Energy Analyzer
An electrostatic probe that determines fraction of multiply charged ions and ion energy distribution. [view more diagnostic details...]
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Page Last Modified: Saturday, 23-Jan-2016 00:55:23 EST
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