RE: Magnetic quenching.

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

Original poster: Marco.Denicolai-at-tellabs-dot-com 

Hi Dave,

 >
 > Original poster: "David Thomson" <dave-at-volantis-dot-org>
 >
 > Hi Marco,
 >
 > Today I built a spark gap out of two 3/4" diameter tungsten
 > carbide balls
 > (ordered through McMaster Carr).  The balls were brazed to
 > 1/8" thoriated
 > tungsten welding rods.  I have a photo of the spark gap, but
 > my host is
 > being hit with a denial of service attack.

Great setup! I would like to find here in Finland tungsten carbide balls
that easily.
Would you please tell me what alloy did you use for the brazing? Did you
do it yourself?

<SNIP>
 > spark.  At 2/10"
 > gap it fired at 85 volt on the variac.  The spark didn't
 > extinguish until
 > the potential was down to 48 volt on the variac.
 >
 > I then tried the experiment with the magnets.  At 2/10" the
 > gap fired at 82
 > volt on the variac and extinguished at 55 volt.  The spark
 > window is much
 > smaller with the magnets.

I imagined the magnets oppose to the spark formation, therefore
facilitating its quenching but also rising the triggering voltage of the
gap. You experienced just the opposite of this: a decreased voltage
threshold.

<SNIP>
 > With the magnetic quenched gap, the spark looked like a
 > circular plane.  The
 > perimeter of the circle moved up and down while the center
 > remained more or
 > less between the closest points of the spheres.  The circular
 > plane was a
 > light blue color.  In the center of all this there were two
 > distinct yellow
 > sparks that joined parallel to each other between the
 > spheres.  In other
 > words, there were two distinct types of sparks occurring
 > between the spheres
 > at the same time.

I guess the plane was parallel or perpendicular to the the magnets
faces, was it?

Interesting stuff, I'll try to replicate myself your experiment, even if
I have only two of those ring magnets available. I want to try with a
diverging field also.

Best Regards