Date: Wed, 15 Nov 2000 15:46:47 -0500

Author: Wolfgang Rueckner

Subject: Re: Electron diffraction


The old Welch Scientific 2639 Electron Diffraction Apparatus has a
hexagonal pyrolytic graphite crystal, which gives a monocrystal dot
diffraction pattern, and a polycrystalline sample which gives an
intermediate pattern (beaded ring). There's also a polycrystalline
aluminum sample which gives a ring pattern. Unhappily, Wech Scientific is
no longer. Wolfgang

>Ladies and gentlemen,
>Most of you are familiar with the electron diffraction apparatus,
>available from several sources, that produces a circular diffraction
>pattern from a powdered graphite source.
>Do any of you know of such a setup that uses a single graphite crystal, so
>that you see an array of bright points, rather than the circles, which is
>harder to explain?
>Dick Berg