A5087508881- Plasma Diagnostics and Applications
- Electrohydrodynamics and Fluid Dynamics
- Laser-induced spectroscopy and plasma
- Spacecraft Design and Technology
- Advanced Battery Technologies Research
- Radiation Effects in Electronics
- Magnetic Field Sensors Techniques
- Satellite Communication Systems
- Atomic and Molecular Physics
- Semiconductor materials and devices
- Vacuum and Plasma Arcs
- Space Technology and Applications
- Space exploration and regulation
Georgia Institute of Technology
2024-2025
Glenn Research Center
2019
Laser Thomson scattering is a minimally intrusive diagnostic technique for determining electron temperature, density, and bulk velocity in plasma systems. Advances technology have made possible the application of to electric propulsion-relevant systems, with reported number-density detection limits as low 1×1016 m−3, temperatures from one-to-tens eV. However, implementation laser large vacuum testing facilities, wherein propulsion devices are tested, remains challenge. This work presents...
Laser Thomson scattering (LTS) is a minimally invasive measurement technique used for determining electron properties in plasma systems. Sheath model closure validation requires measurements of the that traverse boundaries between bulk plasma, presheath, and sheath. Several studies have probed radial along surface discharge electrodes with laser-based diagnostics electrostatic probes. These provide valuable insight into this dynamic region. However, sheath calibration property perpendicular...
Noninvasive measurements of electron properties in a Hall effect thruster (HET) are needed to understand the physical processes acceleration region and validate simulations. This paper presents spatially resolved laser Thomson scattering (LTS) across entire HET. The test article is H9, 9 kW class magnetically shielded H9 operated on krypton at facility pressure 1.2 × 10−5 Torr Kr (1.6 mPa). three discharge conditions: 171 V, 35 A, an inner coil current (Iic) 4.11 outer (Ioc) 2.27 A as...
This paper presents spatially resolved laser Thomson scattering measurements in a cathode presheath and describes new approximation for the electric field at plasma-sheath boundary that accounts collisional ionization effects. The is derived from 1D sheath model using asymptotic theory, validated against exact solution of model. examined with experimentally measured profiles electron properties negative glow discharge. are made noninvasive system applied to 20 kV pulsed plasma an electrode...
Magnetically shielded Hall effect thrusters suffer from pole erosion as their life-limiting mechanism. However, the dominant physical mechanism causing this remains unclear, limiting ability create designs that mitigate and predictive accuracy of simulations used to aid in design. This paper provides spatially resolved laser Thomson scattering measurements electron temperature density near field plume a magnetically thruster, traversing front region discharge channel centerline cathode...
Expected high electron mobility and low resistivity along magnetic field lines—as compared to across lines—have led the assumption, or reproduction through a solution energy equation, that lines are isothermal in typical plasma simulations for Hall effect thrusters (HETs). However, inaccessibility of near-field region perturbative nature electrostatic probes have prevented validation these assumptions HETs. This manuscript presents non-intrusive measurements number density temperature two...
This paper describes recent progress at the NASA Glenn Research Center (GRC) in development and demonstration of an integrated high-propellant throughput small spacecraft electric propulsion (HT-SSEP) system based on a Hall-effect thruster. A center-mounted cathode innovative magnetic circuit topology were implemented design thruster to achieve throughput, high performance, efficient packaging. To minimize technical risk, HT-SSEP approach sought limit features materials those with clear...