Special Seminar Series: Plasma Formation and Electrical Effects from Hypervelocity Impacts

Event Date/Time

Location

Bowen Hall
Atrium 222

Series/Event Type

MAE Departmental Seminars

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Sigrid Elschot

Hypervelocity micro particles, including meteoroids and space debris, routinely impact spacecraft and create dense plasma that expands at the isothermal sound speed. This plasma, with a charge separation commensurate with different species mobilities, can produce a strong electromagnetic pulse (EMP) with a broad frequency spectrum. Subsequent plasma oscillations resulting from instabilities can also emit significant power and may be responsible for many reported satellite anomalies. We present theory and recent results from ground-based impact tests aimed at characterizing hypervelocity impact plasma. We also show results from particle-in-cell (PIC) and computational fluid dynamics (CFD) simulations that allow us to extend to regimes not currently possible with ground-based technology. We show that significant impact-produced radio frequency (RF) emissions occurred in frequencies ranging from VHF through L-band and that these emissions were highly correlated with fast (> 20 km/s) impacts that produced a fully ionized plasma.

Speaker Bio

Sigrid Elschot is a professor in the Department of Aeronautics and Astronautics at Stanford University and leads the Space Environment and Satellite Systems laboratory. She studies the space environment and its effects on both the Earth and on spacecraft with a focus on the plasma formed from impacts of meteoroids and debris. Prof. Elschot is the recipient of the NSF CAREER award, Presidential Early Career Award for Scientists and Engineers, and a Department of Energy Early Career Research award. She was selected as a NIAC fellow for her research on impacts on asteroids as well as on for exploring Uranus using CubeSats and has also served on National Academy panels on mitigating near-Earth objects and assessing NASA’s meteoroid and orbital debris programs. Prof. Elschot has co-hosted the National Geographic Channel’s Known Universe series and has appeared in multiple episodes of Nova. Prior to coming to Stanford, Sigrid was a project lead at the Los Alamos National Laboratory developing RF technology for spacecraft to monitor the ground for electromagnetic pulses, and previously at MIT Lincoln Laboratory working in air defense technology and space situational awareness.

Faculty Host

Choueiri

Semester