Electrons in CRT

In a CRT, where do the ejected electrons go after they cause fluorescence on the screen, have they lost most of their energy, or do they actually go through the glass?

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Typical commercial CRTs for televisions or computer monitors have electron guns that work in the range $5-30\text{ keV}$. Such electrons have a very short penetration depth in solids and will essentially all be stopped in the collimator or the glass of the tube.

See the Particle Physics Data Book chapter on the Passage of Particle Through Matter (PDF link!).

The result is that the screen will develop a net negative charge. This is the cause of the build-up of dust on the screen and of the low level discharge that you can feel if you run your hand over a CRT surface after it has been running for a while.

Left to itself the charge bleeds off. Mostly into the surrounding atmosphere, but also into the bulk of the CRT's case.

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If if bleeds off into the case, then isn't there an eventual pathway for them to be recirculated through re-emission? Does your answer take it as a given that the screen is non-conductive? What voltage would the screen reach from accumulated charge before it finds a pathway away? Would a potential on the screen really not affect the path of the electrons (which I think have to be aimed with high precision)? –  AlanSE Jun 22 '11 at 4:21
50 to 120 kV is much too much. typical values are 5 to 30 kV. Exeeding this range would imply a lot of Röntgen radiation, not very beloved in living rooms. –  Georg Jul 7 '11 at 11:37