SEMINAR:- Spacecraft Charging
Spacecraft interacts with space plasmas. Spacecraft charging affects electronic measurements onboard and may be destructive for a spacecraft.
The seminar explains what, where, when, and why spacecraft charging happens. The physical mechanism of spacecraft charging is clearly explained. The ambient electron temperature provides a criterion for the onset of spacecraft charging in Maxwellian space plasmas. Current balance between the various electron and ion currents determines the spacecraft potential.
Material surface properties are important for spacecraft charging. Surface conditions and ambient electron energies can significantly affect the yields of secondary electrons, backscattered electrons, and photoelectrons. The yields are crucial in determining surface potentials.
Photoelectron currents are usually larger than ambient electron currents but photoelectrons have very low energies. Both positive and negative voltage charging can occur in sunlight. If time allows, some mitigation methods will be discussed.
講者：Dr. Shu T. Lai (Space Propulsion Laboratory, MIT, Cambridge)