Unless there is a fairly dense atmosphere in the chamber, why is the beam visible?
Seriously Bill S you don't get it?
The beam is visible BY DESIGN you place a gas in that reacts with the energy range of the electrons. The light will spread randomly in all directions from the collision that absorbs the electron. So you lose one electron and gain a photon emission from that point. It's very straight forward.
When I do it for kiddies I use a single electron source with a detector at the electron exit point that emits a sound and a photo multiplier to detect the flash. You either get the sound (the electron got thru with no collision) or you get a flash (collision happened). You never get both and most kiddies instantly get it.
The fact you can see the beam is basically an inefficiency of electrons being absorbed before striking the screen for display which is the purpose of a CRT.
Anyhow that about all I have to say on the matter and I don't intend to debate it because this is like kiddie level physics. This is not something I can take seriously and it smacks of Marosz like discussions completely pointless and very stupid.
Cathode rays are invisible, but their presence was first detected in early vacuum tubes when they struck the glass wall of the tube, exciting the atoms of the glass and causing them to emit light, a glow called fluorescence
because thats what we wanted to do by using a specific gas ... now do you really want to continue to discuss stupidity? I was getting a really good laugh, it should have taken anyone around 10 sec search to find the beam is normally invisible, except for with the Science a GoGo forum and some of it's whacky inhabitants.
Trainwrecks are can be interesting to watch
