1. Lunar dust transport investigation in laboratory plasmas
X. Wang, M. Horanyi and S. Robertson

2. Dust Transport above the Lunar Surface
The image of lunar horizon glow taken shortly after sunset [Criswell, 1973]

3. Sketch of linear bright streamers by astronauts
Dust Transport above the Lunar Surface
Sketch of linear bright streamers by astronauts

4. Dust Transport on A Surface in Plasma

6. Dust spreading process after plasma is turned on
Observations
Initial Pile
Uniform Spreading
Dust spreading process after plasma is turned on
Bull’s Eye Pattern
Dust Ring
Insulator
Initial dust pile
6 mm
Dust hopping

7. Potential contours above an insulating disc sitting on the graphite surface biased at -80V
Potential Dip

8. Dust transport in plasma with an electron beam
Emissive probe
Filament
Dust pile
Graphite plate
Vacuum
pump
Filament & Mesh
CCD camera

9. Currents to the graphite plate surface
Jb is electron beam current density and is obtained from a Lamgmuir probe I-V trace.
Je is electron current density.
Ji is ion current density and equals
Jse is secondary electron current density and Jse = kJb.

10. Sheath profiles with Jb  Ji
Secondary electrons are not negligible when beam energy is greater than 60eV.
E// is pointing inward.
E is increased in an order of magnitude.

11. Dust transport observation (Eb=70 eV)
Potential contours