Help with High Voltage Pulser/Receiver (until 500Volt/10ns Rise Time)

Hello, I'm new here.. I'm from Venezuela, and I'm doing an internship for I graduate the next year of Electronic Enginnering. My proyect is to make a generator of high voltage pulses (spikes) with rise time of 10ns or less and pulse width variable between 100ns to 500ns... This is for connect it to a pizoelectric transducer. I also need to make the receiver for it.

I've a basic circuit that I'm using for generates spikes of 200Voltios with more or less 10ns rise time, but when a increment the voltage the rise time also it grows.. so I need turn on the mosfet more quickly.. The basic circuit that I'm using is turn-on and turn-off a mosfet IRF840 that charge and discharge a capacitor through a resistor. I'm turning on the mosfet with a pair of N and P channel Mosfet, IRF9120/IRF110.

IF somebody can help me, I'll been thankful... My email is snipped-for-privacy@gmail.com

p.s.: sorry for the errors in the message, i'm still learning english

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You might need to build a Pulse Forming Network to get the rise time. It will need to match the impedance of the transducer, which is not trivial at all, and the pulse width is not continuously variable. But you did not say that you need that.

Another possibility, If the power level is not great, is avalance transistors. Zetex makes them.

Maybe, but what You really need is more current dumped into the mostly capacitive load and charge it faster. It is the results that count.

It is relatively easy to get/build drivers for MOSFET's that will push an arbitrarily large current into the gate (well, limited by the max gate voltage and the bonding wire).

Maybe you have to run from 500 V (or more) and simply clamp the voltage across the transducer.

It will behave differently from a simple capacitor - specifically it will have resonances and my bet is that the impedance will vary depending on power level and the media it is working in.

Designing for something else than the real thing is a waste, IMO, and I would not bother with it.