[Amps] why a tube fails ?

[Charles Harpole]

Some time ago I asked WHY DOES A TUBE FAIL?
Or What happens when a tube fails or becomes "soft"?
 
I hope to get a discussion about this matter and electric flow generally.  I am asking this question on the ATOMIC LEVEL.
 
The best answer I have heard is that the vacuum inside the tube is not perfect and the tiny amount of oxygen inside does oxidize or interact with the metals inside and eventually breaks one of the metal parts through deterioration of one spot which becomes thin and then separates via the chemical changes of the metal in the presence of oxygen (a process often called "rusting").
 
Then what happens when a tube gives low output but is not dead?  Is it the case that the "rusting" has reduced the area of conductivity (a part is smaller but not broken) and the output drops?   Is this how the tube becomes "soft"?
 
Then, the allied question arises about the flow of electrons as it relates to tubes.  The common understanding is that the element in the tube is heated causing additional excitation of the atoms (electrons will leave their atom more easily) and, that is combined with the application of an electric current which forces an exchange of electrons with a net increase of more electrons ending up in one metal part of the tube compared to the other part.  Those extra electrons must be ions (electrons not attached to any nucleus), yes or no?  If they are not all ions, then if electrons are actually added to an atom, then does that change the chemical composition of the metal (a change of its characteristics as given by the Periodic Table of Elements)?  That is, with the addition of electrons, does that make the matter a different element?
 
So then is the collection of extra electrons on one part inside the tube then "siphoned off" and that becomes the tube's output?  More electrons are "pumped in" by the flow of current into an emitting part?  Then, how is GAIN obtained ?  That is, what happens inside the tube to increase the flow of electrons beyond what is pumped in ?
 
Inquiring minds want to know.  Tnx, 73, Charly K4VUD  
 


Charles Harpole
k4vud at hotmail.com