RE: Flash Tubes

Jimmy & List,
Last week I exchanged info on the topic of Flash Lamp use as a tesla spark
gap, with John Grissom or De Armond (?).
He come by some really nice big ones.
The imortant parameter is Standoff Voltage as this would be the constraining
While I haven't performed any tests the range is likely around a about kV up
to about 6kV for very long ones.
Not an extraordinary range but one that can be set up to work and take some
DC is preferred because the lamps are rated for polarity, I believe so the
metal ions deposit in a preferred direction - the electrodes are
asymetrical. AC may work but with a shorter life, or ?
In either case this should be LOW PPS unless you can provide a good way to
remove heat (linear tubes used with laser rods are liquid cooled for high
rep rates) 

Dale (I'm the one with the 12 DC to 5kV w.1uF using vacuum relay gap to
achieve 8-10" on demand power arcs)

DH> Just HOW Huge is huge ?

John:Really big.  The entire lamp including metal support is over 14" long.
The bulb
itself is about 2" in diameter.  The anode tungsten is about 1/2" dia by 1
long.  The cathode point is about 1/8"  The gap is about 1/4".  This is
definitely a DC lamp.

> At what voltage does it breakdown ?
>  or what is the maximum standoff V ?

Don't know yet. 
> I have been wanting to set up a Xenon lamp spark gap on my 5kV DC Tesla -
> they would be perfect if the standoff voltage is high enough.
> The quench should be great. The electrodes should have long life (no
> as in a vacuum).

Hmm, that had not occured to me but it surely will work.  I have a krytron,
relic from my nuclear work.  Similar geometery but filled with Kr gas with a
small addition of Kr-85.  The beta field stabilizes the timing of the
which is kinda important in the intended application :-)  Of course, there
only has to fire once.  A xenon arc gap should be a perfect switch for a
coil.  The only potential problem I see is that when this thing is operated
on a
neon transformer, some of the discharge follows the inside of the globe
of in the gap.  This was apparently a problem in operation because the
penetration collars are heavily eroded.

DH> There is info on my <1W 12v batt input DC tesla in the archives. I use a
> uF mica cap for 1.25J to get on demand reliable 8-10 " power arcs.
> The present gap is a jennings vacuum relay "jogged" to stimulate arc jump.
> Full (opposed to 'jog') switching promotes contact sticking (welding).

John De Armond  johngd-at-bellsouth-dot-net    Neon John's Custom Neon Bendin'
Glass 'n Passin' Gas"

-----Original Message-----
From: Tesla List [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, March 27, 1999 1:21 PM
To: tesla-at-pupman-dot-com
Subject: Flash Tubes

Original Poster: "JimmyD" <jim_del-at-email.msn-dot-com> 

I was toying with the idea of using flash tube (more like the standard photo
strobes) to be used as a sealed spark gap for tesla use.  Is this feasible
or am I way off base??