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Re: pure water capacitor?



Hi Mark,
              nice try - if any soluble ions at all, even from the air, get
into the water your cap is shot.  For starters the glue you'd use on the
plexiglass would leave plently of nicely water soluble solvent behind.

Regards
Nick Field

> Original Poster: "Mark Broker" <broker-at-uwplatt.edu>
>
> I'm a very new member to the TC community.  I've been interested in
> building one, or two for quite some time, but have never had the
> opportunity ($$$, tools, ect) until recently.
>
> I'm a senior majoring in Engineering Phyisics (don't ask....) and am
> involved with the SPS (Society of Physics Students).  The SPS occasionally
> gives physics demos to local schools.  We have a POS 250kV 1/2 wave TC
that
> must be 20 years old.  I thought that a nice medium-sized 1/4 TC might
make
> an excellent "gift" to the SPS as a going-away gift.
>
> I've been trying to do some research regarding design issues, when I came
> across a list of dielectrics for some materials for use in capacitors.
The
> dielectric constant for pure water is around 85 with an infinite breakdown
> voltage!  This means that two 12" x 12" plates spaced 1/8" apart will give
> a capacitance of .020uF!  I thought it would be a pretty sweet idea: a
pure
> water cap in a plexiglass (or lexan (?)) box.  But, I have NEVER seen this
> mentioned anywhere I've looked.  The only problem I can see is
> contamination: everything has to be 110% clean before adding water.  This
> is do-able.
>
> Are there any reasons why I shouldn't try to use this?
>
> For the record, I'm looking at a 15kV/120mA+ NST.
>
> Thanks
>
> Mark
>
>
>