Charging/Discharging of Space Shuttle Tile Material under Irradiation

Charging, charge storage, and pulsing phenomena are investigated in silica shuttle tiles under electron irradiation. The glass coating creates discharge pulses under the irradiation conditions which, as theory and past experience indicate, would produce large electrostatic fields. The glass fiber response is dominated by secondary electron phenomena during irradiation, but after irradiation micropulses occur for days. Charge is stored for days after the irradiation as would be expected in silica.