Go over to the google group for tek scopes and ask there.
I remember seeing a video from about 1960-something that showed
a slow motion picture of the electron gun ejecting itself
out the face of the tube.

What would also be kind of neat in making a picture tube implode is to place it
in a pressurized chamber and then increase the chamber's internal air pressure
beyond the structural limit of the tube inside, eventually causing it to
implode.

Now, does such a pressurization chamber exist to try it out? - Reinhart