Generation of Bubbles in Glass Insulation Layers of the MC2730 Radioisotopic Thermoelectric Generator.

摘要

Hot-stage microscopy, residual gas analysis, and infrared transmission techniques were used to study the origin of bubbles or voids in the glass insulating layers of the MC2730 Radioisotopic Thermoelectric Generator (RTG). It was found that at temperatures above 1140 exp 0 K, H sub 2 gas was generated through the reduction of water in the glass by the SiGe alloy. It is suggested that voids were formed in those glasses which have low gas permeabilities because H sub 2 was trapped at the interface. The formation of these voids was eliminated by restricting the fabrication temperatures to below 1140 exp 0 K.