Development of Analyzing and Monitoring System for Charging Process in Dielectric Material in Space Environment.

Charge accumulating process in PMMA under electron beam irradiation was observed using the PIPWP method. To oberve the characteristics of charging process, the apparatus of PIPWP method has been modified. Using the improved system, the real time measurement of charge distribution in PMMA was carried out under electron beam irradiation for 5 minutes. The increase of the electrons injected into PMMA was clearly observed with increase of the irradiation time. From the results of the charge distribution, the change of the electric fields and potential were also calculated. Furthermore, the decay of the charge distribution after irradiation was observed. From these results, it is proved that the real time measurement during irradiation is possible. In other words, a monitoring system of electron beam irradiation can be developed in near future.