Re: electron diffraction tube

[Bob LaMontagne <rlamont@POSTOFFICE.PROVIDENCE.EDU>]

Bernard Cleyet wrote:

> Al2O3?  I don't think so.

And rightly so! Our instruction sheet is very old - someone had scribbled "aluminum
oxide" in the margin and, unfortunately, I didn't check further. It's simply
polycrystalline aluminum. I sent a correction to Bill off list when I discovered the
error.

Some additional information on the tube - The target is divided into quadrants. The
upper left quadrant contains (as you see it projected on the screen) both the powdered
and small thin crystalline form of the Graphite. The other 3 quadrants contain the
polycrystalline aluminum - lattice constant 0.404145 nm.

It's a dramatic demonstration of  diffraction due to the wave nature of the electrons
in the tube. We have one of the newer tubes produced by Leybold Didactic  (sold by
Klinger Educational Products), but it doesn't have the clarity of the old GE device.

Bob at PC

> > wmw wrote:
> >
> > > We are attempting to resurrect an old electron diffraction experiment using a
> > > General Electric Z4904 P4 tube. Does anyone have information on this tube,
> > > such as the nature of the targets? Thanks.
> > >
> > > Bill Wehrbein
> > > Nebraska Wesleyan University
> > > Lincoln, NE  68504-2794