Re: Slow Wave Helical Resonator Experiment

Tesla List wrote:
> Original Poster: Terry Fritz <twf-at-verinet-dot-com>
> Hi All,
>         This is an old subject but tonight I repeated an experiment
described in
> the paper "Tesla Coils: 1890-1990  100 Years of Cavity Resonator
> Development" by James and Kenneth Corum.  In that paper, they describe a
> phenomena where the voltage on the secondary rises by standing waves in the
> secondary after the primary spark goes out.  They describe how the Tesla
> coil behaves as a "velocity inhibited quarter wave resonator".  In this
> paper they describe the secondary voltage increasing to very high values
> after the primary spark has gone out.   Apparently over 10 times what it
> was during the ring-up period.  Those that have studied their paper will
> recognize this as being the subjects of Figures 4 and 5 in that paper.
> They also describe the "coherence time" as the time it takes for this
> voltage rise to reach a maximum.  This is under low loss or no breakout
> conditions.
>         At:
> http://www.peakpeak-dot-com/~terryf/tesla/misc/corum.gif
> are the scope waveforms that show secondary terminal voltage (top trace
> 200kV/div) and primary current (bottom trace 100A/div) that I measured
> while repeating their described experiment on my system. This was with no
> breakout on the terminal.  The coherence time they describe should be 114us.
>         As the scope picture I posted shows, there was absolutely no
> voltage rise. The primary circuit quenching is clearly defined in the
> bottom trace occurring at 180uS (50us/div) on the fourth notch after the
> initial burst began. The secondary voltage at 294uS (180+114) appears very
> stable at ~70kV peak with no voltage rise or any evidence of the effects
> described in the Corum's paper.
>         Many have questioned this part of the paper.  No one has been
able to
> reproduce the results or claims this paper makes.  There are obvious
> theoretical and conservation of energy issues with this phenomenon as well
> which tend to conflict with the paper's claims.  Many people have failed to
> reproduce this and I now add myself to this list.  This paper was written
> in 1990 and we obviously know much more now than was known then.  There is
> probably no value in rehashing this subject too much but I had the
> equipment setup and I was curious to find the answer for myself as well...
>         Terry Fritz
>         terryf-at-verinet-dot-com

The laws of physics and nature haven't changed any since that paper was
written; they were as thoroughly understood then as now.  I'm sure your
waveforms present the correct picture for any resonator operated in a
useful mode.