💡 nano-second high voltage generators are optimal for generating and sustaining plasma in various applications. Plasma, acting as a dynamic load, initially resembles an open circuit. However, once fully established, it transitions to behaving like a short circuit or very low impedance load. Consequently, Solid State Marx Generators (SSMG) encounter two types of reflections: 
↳ Positive reflections: When the plasma load initially behaves as an open circuit
↳ Negative reflections: When the plasma is fully established).

🌏 To minimize or avoid these reflections, solutions are proposed:

➊ Negative Reflections: 
To mitigate negative reflections, parallel diodes are employed at each stage of the SSMG. These diodes are designed to bypass and prevent transient pulses from reaching delicate switches and capacitors. Furthermore, the plasma load should be fed by the SSMG via a 50-ohm cable, to limit current flow through switches.

➋ Positive Reflections: 
When the pulse rise exceeds the wave propagation time from the generator to the load through the high voltage cable, the system will not experience any reflections. However, if the pulse rise is lower than the wave propagation time, positive reflections become unavoidable and may potentially damage high voltage stage capacitors of the SSMG and distort incident high voltage pulses. In this case in depth analysis is required to prevent avoidable damage.

🌴 Simulations:

In order to analyze these reflections, a 12-stage Marx generator has been simulated using SIMULIA CST. In this simulation, a dummy high load is employed to mimic the initial open load condition of the plasma. The pattern of the electric field illustrates the propagation of incident and reflected waves (for first 15 nano second only). This simulation provides valuable insights into the behavior of the system and helps in understanding the dynamics of wave propagation and reflection within the Marx generator setup.

Voltage waveform:
https://lnkd.in/eZSPikMp