Quantifying effects of reference surface area ratio on Langmuir Probe-induced spacecraft charging
Is this project an undergraduate, graduate, or faculty project?
Undergraduate
Project Type
individual
Campus
Daytona Beach
Authors' Class Standing
Jonas Rowan, Senior
Lead Presenter's Name
Jonas Rowan
Lead Presenter's College
DB College of Arts and Sciences
Faculty Mentor Name
Aroh Barjatya
Abstract
The use of Langmuir-type probes (LPs) to determine plasma characteristics by measuring collected current has been ubiquitous in the last century, particularly for in-situ measurements of satellites and sounding rockets. It is known that if the potential applied to a LP is relative to reference electrode of small enough size, the act of measuring can cause distortions to that reference potential. In spacecraft, the reference electrode is often the spacecraft body, thus, LPs usually cannot be usefully flown on small spacecraft (especially cubesats) without significant post-processing of data to correct for this shift in floating potential. While this effect has been predicted and documented, no systematic experimental attempt to quantify these effects have been made. To rectify this, a small “satellite” was constructed from a Floating Potential Probe (FPP) and Sweeping Langmuir Probe (SLP) mounted on conducting metal boxes, and placed in a plasma environment with known parameters. The ratio between surface areas of the SLP electrode and reference electrode (the conducting surface of the rest of the satellite) was adjusted in multiple trials, and the FPP recorded the fluctuations in the floating potential.
Did this research project receive funding support (Spark, SURF, Research Abroad, Student Internal Grants, Collaborative, Climbing, or Ignite Grants) from the Office of Undergraduate Research?
No
Quantifying effects of reference surface area ratio on Langmuir Probe-induced spacecraft charging
The use of Langmuir-type probes (LPs) to determine plasma characteristics by measuring collected current has been ubiquitous in the last century, particularly for in-situ measurements of satellites and sounding rockets. It is known that if the potential applied to a LP is relative to reference electrode of small enough size, the act of measuring can cause distortions to that reference potential. In spacecraft, the reference electrode is often the spacecraft body, thus, LPs usually cannot be usefully flown on small spacecraft (especially cubesats) without significant post-processing of data to correct for this shift in floating potential. While this effect has been predicted and documented, no systematic experimental attempt to quantify these effects have been made. To rectify this, a small “satellite” was constructed from a Floating Potential Probe (FPP) and Sweeping Langmuir Probe (SLP) mounted on conducting metal boxes, and placed in a plasma environment with known parameters. The ratio between surface areas of the SLP electrode and reference electrode (the conducting surface of the rest of the satellite) was adjusted in multiple trials, and the FPP recorded the fluctuations in the floating potential.