Title :
Optical measurement of breakdown processes in polymethylmethacrylate under nanosecond pulse voltage application
Author :
Yamada, H. ; Fujiwara, T. ; Taniguchi ; Sato, T.
Author_Institution :
Dept. of Electr. Eng., Iwate Univ., Morioka, Japan
Abstract :
High-speed framing photography has revealed the propagation velocity of breakdown channel in polymethylate (PMMA) to be between 30 and 120 kmf/s for positive 50-kV point voltage. The waveforms of the prebreakdown current in PMMA are essentially the same as those in liquid dielectrics. The breakdown time lag was precisely measured from the current. A linear relation between formative time lag and gap spacing is observed for gap length greater than a critical value, indicating another constant propagation velocity in this region. The velocity is deduced from the relation to be 2.2 km/s. This value is fairly close to that of longitudinal waves in the solid
Keywords :
electric breakdown of solids; high-speed optical techniques; photographic applications; polymers; 50 kV; PMMA; breakdown channel; breakdown processes; breakdown time lag; constant propagation velocity; formative time lag; framing photography; gap length; gap spacing; longitudinal waves; nanosecond pulse voltage application; polymethylmethacrylate; prebreakdown current; Breakdown voltage; Current measurement; Dielectric liquids; Dielectric measurements; Electric breakdown; High speed optical techniques; Optical propagation; Photography; Solids; Time measurement;
Conference_Titel :
Conduction and Breakdown in Solid Dielectrics, 1992., Proceedings of the 4th International Conference on
Conference_Location :
Sestri Levante
Print_ISBN :
0-7803-0129-3
DOI :
10.1109/ICSD.1992.224927
