Improved discharge properties of bulk Na2O-BaO-PbO-Nb2O5-SiO2 glass-ceramic dielectrics through electrode structure design

For pulsed power applications, bulk Na₂O-BaO-PbO-Nb₂O₅-SiO₂ glass-ceramic dielectrics in considerable size (about 150 × 60 × 4 mm³) were prepared via controlled-crystallization route. The discharge properties (mainly the discharge speed dI/dt and the duration time τ) of the dielectrics were investigated. The results show that the capability of charge or energy storage in the bulk dielectrics is relatively lower than that of anticipation based on smaller specimen, due to a serious drop of breakdown strength (BDS) of the bulk dielectrics. Several electrode structures were designed and applied in the measurement circuit to enhance the BDS of the bulk dielectrics. Among which, a bowl-like electrode structure was proved to reduce electrode edge effect most effectively in the BDS measurement and result in the improved dI/dt and τ.