Re: First THOR measurement results

["Barton B. Anderson" <tesla123-at-xxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

Hi Marco, 

Tesla list wrote: 
>
> Original poster: "Marco Denicolai" <Marco.Denicolai-at-tellabs.fi> 
>
> Hello everybody. 
>
> Eventually I got everything setup and working, in order to measure the THOR
> TC 
> performance. 
>
> I did it today and I stored in a temporary web page the most significative 
> oscilloscope snapshots. The address is 
>
> <http://www.saunalahti.fi/dncmrc/work/tempmeas.htm>http://www.saunalahti.f
> i/dncmrc/work/tempmeas.htm. 
>  

I did get the url to work. Need to take out the . at the end of htm. 
>
>   
> The performance achieved was: 
>
> Peak voltage: 14.7 kV 
> Bang energy: 10.8 J 
> Bang rate: 354 BPS 
> Total power: 3727 W 
> Max streamer to ground: 8.2 feet (2.5 meters) 
>
> You can see a snapshot of the primary voltage in the web page (4th picture
> from 
> up). Now I have got 2 questions for you all. 
>
> Question 1 
> --------------- 
> You can see in my web page (first 3 shots) the primary voltage when 
> breaking out 
> into air, to ground or with no streamers. 
> 1. Discharging to ground sucks quickly all the energy away. That's OK. 
> 2. To discharge into air, I needed to add a copper stick on the top of the 
> toroid: only then I had a secure discharge into air or to a nearby grounded 
> rod. 
> Breaking into air sucks pretty quickly too all the energy away and there is 
> also 
> nothing strange with that. 
> 3. With no copper stick I have difficulties to get any streamer at all. This 
> makes me think that I don't generate enough potential at the secondary to 
> breakout. The toroid r.o.c. is a little too big. But my RSG is unable to 
> quench!!! See the snapshot! 
>
> Question: 
> - do you agree with me about the above? 
> - I think that if I could quench the RSG I could accumulate more charge on
> the 
> toroid, reach the actual breakout threshold and get longer streamers WITHOUT 
> NEEDING THE ROD: do you agree?

Yes, if in doing so you increase the power to the streamer. 
>
> - in order to better the quenching, shouldn't I add a fixed SG set in series
> to 
> the RSG? Wouldn't that be OK?

I haven't done this in a long time, but yes, it should help quench. But it may
not gain you higher voltage at the toroid. My guess would be the heating of the
gap is causing the voltage to breakover at lower voltages than you want. This
will reduce all the other factors with it. You may want to go back to the RSG
and figure out why it is heating. Maybe a little info about it will spark some
experiences from the group. 
>
> Question 2 
> --------------- 
> The performance of Thor (spark length) decreases quite rapidly within 15-30 
> seconds. This is expecially noticeable without the copper rod placed on the 
> toroid: then streamers are quite rare and stop coming within 10-15 seconds. 
> What 
> might be the reason? I suppose the RSG overheating and crippling the
> quenching 
> or what? I have already heard of this kind of behaviour but I can't recall
> what 
> was the explanation. Anybody?

Yep, sounds like heating. 

Bart