Re: Flash Tubes

To: tesla-at-pupman-dot-com
Subject: Re: Flash Tubes
From: Bert Hickman <bert.hickman-at-aquila-dot-com> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Sun, 28 Mar 1999 11:27:19 -0700
Approved: twf-at-verinet-dot-com

Tesla List wrote:
> 
> 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??

Jim,

No such luck! There are a couple of problems - plasma confinement and
reduced gas pressure/current carriers. One desireable property of an
unconfined plasma (for coilers at least) is that it has a negative
resistance characteristic... as long as the plasma channel can expand,
the voltage drop across the plasma will decrease as the current
increases. However, when the discharge is confined, as it is inside a
flashtube, the cool glass walls stop the expansion of the plasma channel
at higher current densities, and the arc discharge is forced to assume a
positive resistance characeristic. Higher current levels now cause a
higher voltage drop across the flashlamp, leading to much larger losses
thant for an in-air sparkgap. Because flashlamps operate at pressures
less than atmospheric pressure, there are fewer current-carriers
available to efficiently handle high current levels. This also causes
the "on" resistance (and losses) to be higher than a simple in-air spark
gap.

-- Bert --

-- Bert --