Help:HOW to generate short pulse with avalanche?

i know AVALANCHE transistors can generate very short pulses
but how to generate the controllable impulse about 1.7ns with 700V ?
Can you post some short pulse generator circuits in my E-mail?
thanks.
E-mail: super_wind2002@sohu.com

you can google this. I saw chinese researchers do a simple strip line gang of transistors, i think it was called a marx circuit, but cant remember. the transistors are avalanche biased, and the whole thing pulses rapidly when triggered. they were doing 1000 v as i remember. cheap and simple and very fast. Another way to keep in mind is put a piece of coax stub or stripline track to provide a negative echo that trims the fall time. i will see if i can find ref. had photos as well.

---------- Post added at 11:28 ---------- Previous post was at 11:09 ----------

look up marx generator in wikipedia. thats the circuit you are looking for. This is not simple cookbook hookup stuff - you should know microwave-style layout and understand avalanche theory. but the citcuit is well established and relatively easy to do. I did see several examples in the literature of working circuits. You have to gang about 10 transistors in series and either pulse a single gate or let v exceed breakdown. Then you get a domino effect, as they all fire off.

Here is some Chinese papers, yuyin , you can read.