RE: RF Shielding for CRTs

["Langenegger, Armin" <alang@allsaintshealthcare.org>]

		"Weren't the old vacuum tubes used in TV sets a source of
x-ray exposure?
		Glen
		glen.vickers@ucm.com"


		Yes they were. These days the acceleration of the cathode
electron beam is about 20keV for most color sets. As these electrons
interact with the phosphor on the TV tube surface they slow down and produce
bremstrahlung with a maximum energy of around 20keV. This is in the
mammography range and most is absorbed by the thick glass of the TV tube.
Minute amounts will pass through the tube and will be absorbed by the air.

		Many old sets had thiner glass on the top and bottom of the
tubes and I remember many stories about the family cat that lay on top of
the TV becoming sterile after many years. (Urban Myth?)

		But the original question was shielding for RF. I also
believe that this is not a problem.


		
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