Marx generator (fwd)

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Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Fri, 18 Nov 2005 13:11:52 +0100
From: Herwig Roscher <herwig.roscher@xxxxxx>
To: hvlist@xxxxxxxxxx
Subject: Marx generator


List,

I have just finished building my first Marx generator and I am about 
tuning it.

Capacitors			3.33 nF
Resistors			2 MOhm
Stages 			25
Loading voltage	20 kV
Spark gaps		0.28"
Erected C			133 pF
Bang voltage		500 kV
Bang size			16 Joule
Discharge length	13.4"

However I would like to ask the more experienced builders for some 
help:

Q1:
The distance, a voltage of 1 kV can jump, usually is said to be 
0.013". For Marx generators I found values of about 0.04" as well.

Other Marx builders claim:

0.052"		Rapp
0.045"		Steve Ward
0.052"		Kronjaeger
0.050"		Mike Gilchrist

My system jumps only 0.027"/kV. Why? Is this a question of the form 
of the electrodes?

Q2:
Other Marx builders get:

1.75"/Joule		Rapp
1.92"/Joule		Steve Ward
1.83"/Joule		Mike Gilchrist

I only get 0.9"/Joule. Again: Why?

Q3:
During and after completion of the bank loading there is no sizzling 
noise. Therefor I assume, that there is little or no corona at 20 kV. 
Is it possible, that at ignition of the bank there is too much corona 
at 500 kV?

What are the secrets of Marx tuning? Any help would be appreciated 
very much.



Bye		Herwig

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Greed is the root of all evil !
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