Assertion: cathode | /r/HasProperty | a nickel tube
Facets:
value: in most vacuum tubes
type: LOCATION
value: with the filament inside it
type: OTHER
Source sentences:
text: For example, in most vacuum tubes the cathode is a nickel tube with the filament inside it, and the heat from the filament causes the outside surface of the tube to emit electrons.
text: For example, in most vacuum tubes the cathode is a nickel tube, coated with metal oxides.