<<I remember years ago at Sandia Labs folks would expose small slabs of
clear plastic (maybe 15cmx15cmx1cm?) to the Van de Graaf beam. The slabs
could be stored for a long time and then when struck with a sharp point
(hammer and ice-pick) would discharge the trapped electrons forming
handsome dendritic patterns inside the plastic. >>
Believe it or not, I saw this for sale recently in a small catalog. For
$20, I think!! I have it at school if you'd like the name of the catalog,
etc.
By the way, my name is Aminthe Broussard and I am new to this list. I
teach physics at New Iberia Senior High School in New Iberia, Louisiana.