We study weakly continuously Urysohn spaces, which were introduced in [Z]. We show that every weakly continuously Urysohn w∆-space has a base of countable order, that separable weakly continuously Urysohn spaces are submetrizable, hence continuously Urysohn, that monontonically normal weakly continuously Urysohn spaces are hereditarily paracompact, and that no linear extension of any uncountabl...

Electron plasma columns continuously injected into a Malmberg-Penning trap display a rich evolution. Electrons emitted from an illuminated photocathode are trapped in the electrostatic well formed by the negatively biased photocathode and the trap end cylinder. Initially, the injections form cylinders of uniform density. As the density increases, the columns hollow in an attempt to match the po...