Re: spark gap design

To: tesla-at-pupman-dot-com
Subject: Re: spark gap design
From: "B**2" <bensonbd-at-erols-dot-com> (by way of terryf-at-verinet-dot-com)
Date: Sat, 29 Aug 1998 13:08:45 -0600
Approved: terryf-at-verinet-dot-com


Hi Terry, All,
    Why not keep the pipe stationary and make the spark move?  A rare
earth magnet with flux apropriately directed would cause the spark to
slide along the contact surfaces of the pipe.  This would limit the
heating related damage caused by the cathode spot.  It might also have
interesting effects on the quench.  Dayton Grainger did research on a
lightning arrester that consisted of an annular gap with a magnet
inside.  The arc would move at very high speed around the annular gap
due to the j cross B force from the magnetic field.  The arc damage to
the gap was minimal.

    In the American Journal of Physics (if memory serves) an
experiment was done to attempt to stabilize the wild cathode spot.
The apparatus consisted of two flat rotating disks of (copper?)
counterrotated at high speed.  A speed was found at which the cathode
spot stabilized.  I think that the disks were edge on.  That is all I
can recall as the article is under 3 meters of mail and hamfest
goodies.  If I ever find it I will repost with a citation.

Barry

<<<  This is a very interesting thought!  I have never tried it but I will
look into this.  Being able to move the arc along two surfaces would keep
the arc in a cool region and even out gap wear.  I wonder it the magnetic
forces will be able to overcome the path presented by the hot ionized gases
but even just small push along the conductors by be enough to provide
improment  --  Terry  >>>