Re: Conserving Q / space charge in insulators

[brian whatcott <inet@INTELLISYS.NET>]

At 06:01 1/29/99 -0500, John Denker wrote:
> Good insulators -- the best insulators -- will carry charges not just on
> their surfaces but also throughout their volume.  ....
> (It is amusing that although the initial process of charging the dielectric
> is lossy, after it is sufficiently charged up this might be a reasonably
> non-lossy capacitor.)

> The story of how real insulators work is quite interesting: traps, charge
> injection, Mott localization, Anderson localization, and all that.  But
> it's a bit complicated.  Most elementary physics books say nothing about
> any of this.  Most graduate-level solid state physics books cover only
> metals and semiconductors, and tend to give the impression that "insulator"
> is just the name we give to large-gap semiconductors ... which is horribly
> far from being the whole story.
> ...
> I don't know of any references on how insulators work that would be
> suitable for typical students or non-experts of any kind.  Back when I was
> a student I actually traveled to the Xerox research lab in Rochester. ...
> Cheers --- jsd
I found this account very informative and confidence building.
Forgive me for the skeptical frisson when John allowed that Xerox Rochester
 had knowledge unknown to most texts, ug and graduate students ( and so by
reductio, most physics profs I suppose?)

 If I recall, this applied lab is there not only to keep up with the
Kodak-Jones's but to resolve thorny issues like how to stop Xerox copiers
from their jamming propensity (Secret of the universe? Straighten the
paper feed path!) and how to make the fabulously expensive semiconductor
coated drums on copiers at a more acceptable price from less polluting
 materials - not to mention how to reduce the ugly gossip about the heavy
 ion count and small particle contamination around the copier (that their
 ads would have you believe the clerical steff is in love with...)

 But I am too cynical by far - and I am glad John can offer his valuable
contribution to Ludwik's work - L. has been stubbornly exploring areas of
inexplicable variation in experimental results - possibly the single most
valuable lab experience students could possibly have?
 It's just not cut and dried out there....  :-)

But to get to the point: at one point John seems to say that the best
insulators show the best space charge, but many will break down before
showing their space charge capability.
Is polystyrene a good space charge insulator?

Brian
brian whatcott <inet@intellisys.net>
Altus OK