Hollow cathode tube
From MediaWiki

A hollow cathode tube is a vital part of space bridge technology. Ideally, it should be connected to a plasma bridge neutralizer.
Fiction
Transformers Animated cartoon
The Constructicons were carrying a hollow cathode tube across the Decepticon mine base when Bulkhead told them that it needed to be connected to the plasma bridge neutralizer. Professor Sumdac disagreed, saying that it would risk overloading the positive and negative grids. After a few minutes of carrying the cathode tube back and forth as the pair disagreed, the Constructicons dumped it on the floor so they could take a break. A Bridge Too Close, Part I

