Moon

ESPG Chamber

Charged Surface (Radiation)

Solar wind, solar energetic particles, galactic cosmic rays

Flood beam of electrons and vacuum ultraviolet (VUV)

Ambient Pressure

10^-12 torr (night) to 10^-10 torr (day)

10^-6 ~ 10^-5 torr (< 10^-5 torr for e-beam gun operation)

Surface Particle

Lunar Regolith

Lunar regolith simulant (Planet LLC, type JSC-1A)

Size

< 45 mm (40wt % of soil)

700 nm ~ 1 mm

Property (dielectric)

Dielectric (insulator)

Dielectric

Property of the surface

-    Extremely fine

-    Electrostatically charged particles

-    Electrostatic dust transport

-    Extremely fine

-    Exposed to high electric field

-  Low humidity

Magnetic field

No global field, Isolated paleofields, (magnetic field strength: 3 × 10^-9 ~3.3 × 10^-7 tesla)

No additional magnetic field except earth magnetic field (but shielded)