Figure - available from: Review of Scientific Instruments
This content is subject to copyright. Terms and conditions apply.
Source publication
The Tesla-type pulsed power generator based on transformer oil is limited by volume and weight, which affects its suitability for mobile platforms. In this paper, a double-width pulse forming line (PFL) based on high-energy-density liquid medium Midel 7131 was designed, and a compact, high-repetitive pulsed power generator was developed. The struct...
Citations
Thermal runaway and electrical instability in pulsed thyristors under repetitive pulses critically limit the reliability of solid-state and compact high-power pulse generators. However, the bidirectional electrothermal effects of pulsed thyristors under repetitive pulses have not been studied. In this paper, they were explored based on mixed semiconductor device and circuit simulations and scaling experiments. The results show that within a ten-microsecond pulse, the maximum temperature rise occurs in the P2 region between the amplifying gate and the cathode under diode protection, whereas that occurs in the J1 junction near the anode without diode protection. The global maximum temperature decreases, and the heating region gradually expands with increasing pulse width. As the repetition rate increases, the temperature of the thyristor case is higher within the same testing time. Affected by higher temperature, the voltage drop and peak power dissipation increase and the anode current decreases. The residual temperature in the previous pulse further increases the heat generation in the next pulse. The electrothermal bidirectional coupling relationship under repetitive pulses was established theoretically, which can guide the application of high-power pulse generators in repetition rate mode.
The concept of the coaxial cascade-line rectangular-pulse generator is put forward, the basic idea of which is to cascade two coaxial lines of equal impedance together and make one line turn around to let the two lines use a common middle tube. The obvious feature of this kind of generator is that it can form a rectangular pulse with a width of 4 times the electrical length of one line. Compared with the conventional single-tube generator, the total stored energy is doubled. Namely, the output pulse width of the coaxial cascade-line generator is doubled for the same output voltage, which is beneficial for miniaturization. The principle of the cascade pulse forming line is first introduced; then the coaxial cascade-line rectangular-pulse generator is suggested. The simulation results prove the feasibility of the cascade-line generators. Finally, the design of a Tesla-type generator with an output power of 20 GW and a pulse width of 40 ns is presented based on the coaxial cascade-line method.
Published by the American Physical Society 2025
