Re: water as spark gap dielectric

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

At 03:09 PM 4/17/2003 -0600, you wrote:
>Original poster: "Bert Hickman by way of Terry Fritz 
><teslalist-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>
>
>Hi Jim,
>
>Interesting article! BTW, those who are interested can view a copy at:
>http://www.eece.unm.edu/cp3/Publications/Shu.pdf

Good to find a public source.. I found it in an IEEE search


>An external spark gap is still necessary to isolate the water gap while 
>energy is being replenished in the energy storage element. For TC use, 
>this means that we can't dispense with the air gap in series with the 
>water gap, so instantaneous gap losses will be higher. However, if the 
>water gap provides superior quenching ability, the additional gap losses 
>may still be worth it if we can achieve "one notch" quenching at high 
>coupling coefficients.
>
>The water gap recovery curves don't look very promising for single P-S 
>energy transfers. The recovery chart for reasonable bang sizes (Figure 9 
>in the paper) implies that the gap will only recover ~5% of its standoff 
>capability after ~250 uSec pretty much independent of power level. If we 
>use a relatively low frequency TC (say, 50 kHz with a coupling coefficient 
>of 0.22), the time to the first notch is ~2.5 cycles, or ~50 uSec. This 
>implies relatively poor quenching...



However, their gap design wasn't optimized for our application... I thought 
it might serve as an interesting approach.  From a practicality standpoint, 
I'm thinking that a pressurized blown gap might be better. High pressure 
means short gap for the voltage, blown means good cooling/quenching.