Hi,

I am trying to calculate electron propagation distance (dose rate?) in a material.

Specifically my interest is to calculate how much of the beta radiation exits trough the front of CRT, because I cannot find any reliable source for this information.

The only information I was able to find to base my calculations on was

http://www.ptb.de/en/org/6/62/621/beschleuniger/elektronen.htmFrom which I was able to make some guesstimates, that most of the radiation should stop at 0.35mm in case of 25kev beam. The question is then why the CRT tube is so thick, and additionally shielded?

One of the interesting parts I was able to see in the graph, is that at the end of the x axis, the curves start to go perpendicular to the x axis, which would suggest there some sort of effect allows part of the radiation to pass (tunneling effect?).

Can somebody please help me find the correct formula in an understandable form? I am really afraid of getting lost inside "DIN 6800-2" or documents of similar complexity. I promise I will not abuse this dangerous information!

Thank you in advance!