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Re: Streamer Impedance

Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

At 11:29 PM 4/30/2005, you wrote: 
Years ago, Terry somehow determined a streamer is roughly 220K and 6 pF per
foot of streamer length.  (I am going by memory - might not be accurate).

It is 220k + 1pF per foot of streamer length. So a 10 foot streamer would be 220k + 10pF.


Question: Is the 220K value a time averaged value?

Yes. It is the impedance that gives the same voltages when modeled as actual streamers produce.

I am thinking when the
streamer channel is conducting, the resistance would be much lower.  Then
when it is not conducting between bangs, the resistance would be
considerably higher.  So depending on the duty cycle of streamer conduction,
the average resistance would vary - sort of a pulse width modulation effect.
What do you experts think?

It is really much more complex than the simple equation above. But for modeling at least, the equation works pretty well.


I also imagine the higher the BPS, and the higher the average power going
into the streamer, the more ions will in the streamer path, and thus the
lower will be the average streamer resistance.  Your thoughts?


?


Finally, if one is interested in matching the impedance of the streamer to
the secondary impedance, I would think the streamer resistance during the
bang, not the average resistance over time, should be used, yes?


?

Cheers,

        Terry


--Steve Y.