Development of 2.4 ns rise time, 300 kV, similar to 500 MW compact co-axial Marx generator

摘要

Compact Marx generators are known for delivering high power in very short duration and do not require any separate pulse shaping components. The design and operation of 10 stage co-axial Marx generator with fast rise time of 2.4 ns, maximum voltage 300 kV, pulse width 20 ns, energy 4.2 J and impedance 71 Omega has been presented. The Marx generator is capable of delivering the peak power of ～500 MW with 100Ω load. The coaxial geometry is used throughout the system to achieve high value of capacitance and low value of inductance leading to low impedance and also uses single point triggering for erection. The generator is presented with consideration of internal inductance and stray capacitance. The strontium titanate~1 (SrTiO_3) capacitors are used in this experiment due to very low derating capacitance at rated voltage, high dielectric strength and high current capacity. This set-up is pressurized by dry nitrogen air for the charging of Marx to -30 kV. The erected series current is measured by using non-inductive 10 mΩ current viewing resistor. This compact Marx is fitted into a stainless steel (metallic) cylinder (102 mm diam, 730 mm total length). The present Marx generator has been operated for the charging of voltage up to -30 kV. The Marx generator is tested at different charging voltages with 50 and 100 Omega ceramic resistive loads. The measured voltage waveforms and the corresponding data have been given. The output parameter of Marx generator is checked by simulation and experiment. The modeling, design and experimental results of coaxial Marx generator are discussed.