Re: Effect of UV on topload

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

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

PAUL: I SUSPECT SHORT WAVE TO CHANGE THE CONDITIONS SOME WHAT. A GERMACIDAL
SHORT WAVE SHOULD MAKE SOME CHANGES, BUT A LONG WAVE "BLACK LIGHT" SHOULD
HAVE LITTLE IF ANY EFFECT. THE USE OF AN  E-ROM ERACER (SHORT WAVE) WOULD BE
A WASTE OF TIME, IT IS TO SMALL. GERMACILAL LAMPS ARE USED IN SIDE
AIRCONDITIONING SYSTEMS AND MEDICAL EQUIPMENT AND ARE MADE UP TO 30
WATT.THEY DO REQUIRE EYE PROTECTION. A MERCURY LAMP SHOULD ALSO WORK.
   ROBERT  H  

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Fri, 12 Apr 2002 07:34:48 -0600
> To: tesla-at-pupman-dot-com
> Subject: Re: Effect of UV on topload
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Fri, 12 Apr 2002 07:44:47 -0600
> 
> Original poster: "Paul Nicholson by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <paul-at-abelian.demon.co.uk>
> 
> Jim wrote:
>> UV is certainly going to knock some electrons off from
>> photoelectric effect.  Off hand, though, I wouldn't think that
>> the effect is very big for aluminum, etc
> 
> Steve Greenfield wrote:
>> If it were enough to change Q by a meaningful amount I'd also
>> expect it to make breakdown require less voltage, too.
> 
> Terry wrote: 
>> But the sun would heat the coil "considerably" which may hide
>> any solar effects.
> 
> Mike wrote:
>> If he doesn't,  I will let him make use of one of my mercury
>> vapor UV lamps
> 
> Thanks for the various comments.
> 
> Well we know that UV lamps discharge electroscopes, and an EPROM
> erases much quicker under a lamp than outside under the Sun, so
> I guess a lamp would have more chance of affecting a coil, and with
> less heating effect.
> 
> The leakage current, if any, would be proportional to the flux of
> photons with energy greater than some work function, rather than
> the amount of energy in the coil, or to its topvolts.  So I suppose
> it would affect the Q less at high power than low power.  It would
> show up, perhaps, only as a slight linearisation of the tail end of
> an otherwise exponential ringdown, as the constant current leakage
> became a larger percentage of the total loss.
> 
> Looks like another experiment to add to the list then, unless anyone
> can see a reason why it's not worth trying?  For a given UV lamp and
> coil+topload, it should be possible to measure the total leakage
> current by charging the resonator up with a few kV of DC and
> timing the linear rampdown.  That would give enough info to
> calculate the effect on Q.
> 
> And we're left with the corollary,
> 
> e) Does shining UV onto the topload lower the position of the variac
> at which breakout starts?
> 
> I suppose no amount of photo-electrons will help if there's just not
> enough surface field for avalanche multiplication.  But given a coil
> that's already starting to break out, perhaps incident UV will
> increase the amount of streamers by providing more seeds for
> avalanche.
> 
> And what's the effect of UV on the streamers themselves?  Can they
> become more branched, or bushier?   Hmm, perhaps not, I suppose the
> extra few photoelectrons would be negligible compared with the
> torrent of free electrons already in the streamer.
> 
> Having seen an electroscope sit there for ages holding a charge, and
> then rapidly discharge the moment a lamp was turned on, I can't help
> thinking that it would be at least worth checking to see if UV
> illumination has an effect on TCs.
> 
> Well, some food for thought, and some experiments to try for those
> with a UV lamp, TC, flyback circuit + EHT tripler, and a stopwatch.
> --
> Paul Nicholson
> --
> 
> 
>