Re: Magnetic quenching.

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

Hi Sean,

On 13 Mar 2004, at 12:12, Tesla list wrote:

 > Original poster: Sean Taylor <sstaylor-at-uiuc.edu>
 >
 > On Fri, 12 Mar 2004 21:33:06 -0700, Tesla list <tesla-at-pupman-dot-com>
 > wrote:
 >
 > >Original poster: John <fireba8104-at-yahoo-dot-com> Hi,
 > >   I was thinking the same thing but with a complex controller. The
 > >   idea
 > > is that a short burst of high current (large value cap?--include
 > > diodes to attempt to stop ringing) is supplied to a electro-magnet
 > > every half cycle in order to "trigger the gap".This idea stems from
 > > a former post where breakdown voltages were given, showing a lower
 > > breakdown voltage with magnetic flux applied. Also, if is not to
 > > complex,  a current detecting device could be used to tell when the
 > > first notch is reached, triggering another magnetic pulse to quench
 > > the gap. To sum it up a sync trigger and a event(first notch)
 > > trigger for a single electro-magnet.
 > >Feasible, with a lot of work or just random ramblings.
 > >Cheers,
 > >John
 >
 >
 > Just thought of something . . .  First, I was (and I'm sure many
 > others) are thinking the same type of thing - a reverse triggered gap
 > kind of. Trigger exactly when you want the quench to take place.
 > Problem is, if you try to quench on a zero current crossing with a
 > magnet, you won't get anywhere until the current reaches some higher
 > value.  As someone already pointed out, a magnetic quenched gap works
 > by deflecting the arc by "pushing on the moving electrons - F = qVxB.
 > Problem is, for there to be an velocity, there has to be current flow
 > - so at a zero current crossing, there is no force on the plasma
 > channel.  Honestly, I don't see what the advantage is
 > (performance-wise) of a magnetic quenched gap vs. air blown. Seems
 > like the air blown gap would help everything - disperse ions, make the
 > arc path longer to help quenching, and cool the terminals.
 >
 > Sean Taylor
 > Urbana, IL

In my dreams I see a single static gap with a nozzle pointing through
the center and a powerful jet of air puffing through for a mS or two
immediately the first pri-sec transfer is completed. This to be
repeated for each shot (as Tesla might have said :). So, who has the
mechanical facilities to construct a (rotary?) valve that would do
the trick? A compressor and nozzle together with hoses is all else
that would be needed. I'm now thinking I could even make one on the
lathe at work.

Malcolm