Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 1999
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1999dps....31.6107s&link_type=abstract
American Astronomical Society, DPS meeting #31, #61.07
Astronomy and Astrophysics
Astronomy
Scientific paper
Illumination of surfaces in space by solar ultraviolet light produces photoelectrons which form a plasma sheath near the surface. Dust particles on the surface can acquire a charge and be transported horizontally and vertically by electric fields within the sheath. On the moon, suspended dust grains have been observed on multiple occasions, and there is evidence for horizontal lunar dust transport. Photoelectron production and dust particle charging are also expected to be significant near the surface of Mars. Understanding the photoelectric charging properties of dust can help explain the observed dynamics of lunar dust and help predict the behavior of dust on surfaces of planetary satellites, asteroids, planetary ring particles, and planetesimals. In addition, any human or spacecraft activity on planetary bodies is affected by dust dynamics near the surface. We have examined the photoelectric charging of dust dropped through UV illumination and dust dropped past a UV illuminated surface having a photoelectron sheath. Experiments are performed in vacuum with illumination from a 1 kW Hg-Xe arc lamp. The lamp produces a spectrum down to ~ 200 nm ( ~ 6.2 eV), and the photoemitter is a 12 cm diameter zirconium plate. Dust dropped through UV illumination loses electrons due to photoemission, while dust dropped past an illuminated surface gains electrons from the photoelectron sheath. Initial results are consistent with expected charge calculated from the work function of the materials, the energy of incoming photons, and the capacitance of the grains. Photoelectric charging experiments have been done for several different kinds of dust 90-106 mu m in diameter. We will present the results of these experiments and compare the charging properties of zinc, copper, graphite, Martian regolith simulant (JSC Mars-1), lunar regolith simulant (JSC-1), and lunar soil from an Apollo 17 sample. This research is supported by NASA.
Colwell Joshua E.
Horanyi Mihaly
Robertson Scott
Sickafoose Amanda A.
No associations
LandOfFree
Photoelectric Charging of Dust in Space does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Photoelectric Charging of Dust in Space, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photoelectric Charging of Dust in Space will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1557643