Research on a Folded Blumlein Line Using Kapton Film as Dielectrics

In this project, a Blumlein line with a folded parallel-plates configuration using Kapton film as dielectrics was investigated. The characteristic parameters of this Blumlein line were analysed theoretically. The electric field distributions under different inner radii of the folded part were simulated. The output waveforms on the match load were also simulated by means of an equivalent electric circuit. According to the results of the theoretecal analysis and simulation, a Blumlein line with the folded parallel-plates configuration with an output voltage of 500 kV, a pulse duration of 100 ns, and a characteristic impedance of 4.773Ω was designed and manufactured. The experimental results properly demonstrated the wave transmitting process in the Blumlein line, and provided the voltage waveform of 500 kV and the current waveform of 50 kA with a pulse duration of 150 ns. Some engineering problems such as the edge electric breakdown and measuring precision by a resistance divider were revealed, which must be solved in future work to produce a more compact transmission line.

Structure and dielectric properties of NBT-xBT-ST lead-free ceramics for energy storage

(0:74-x)(Na_(0.5)Bi_(0.5))TiO_(3)-xBaTiO_(3)-0.26SrTiO_(3)(x=0~0.1)(abbreviated as NBT-xBT-ST)lead-free ceramics were fabricated by a solid-state reaction method.The effect of Ba doping amount x on the structure and energy storage properties of NBT-xBT-ST ceramics were investigated.All the NBT-xBT-ST ceramics showed single perovskite structure with a pseudocubic phase.Ba doping effectively suppressed grain growth,in favor of forming small and uniform grains.The ceramics with a composition of x=0.04,an optimized energy storage density(γ=0.47 J/cm^(3))and efficiency(η=48:67%),under an applied electric field of 50 kV/cm,should be a candidate for solid-state compact pulsed power capacitor materials.