A couple of years ago I bought a few novelty key rings containing tritium radioluminescent lamps.
Obviously, when you read the marketing spiel it goes on about how the beta particles can't get out of the acrylic shell, etc.
And, tritium is a pure beta emitter - it's got a nice simple decay chain: no branches and no intermediate levels - just an 18.59 keV ß.
By chance, today, I happened to test it with a Geiger counter - and sure enough it consistently read about 70 counts /s above background. Presumably this is due to bremsstrahlung generation in the acrylic - whatever it is, it certainly isn't very penetrating (it won't go through a finger).
But maybe someone here has a better idea?
Obviously, when you read the marketing spiel it goes on about how the beta particles can't get out of the acrylic shell, etc.
And, tritium is a pure beta emitter - it's got a nice simple decay chain: no branches and no intermediate levels - just an 18.59 keV ß.
By chance, today, I happened to test it with a Geiger counter - and sure enough it consistently read about 70 counts /s above background. Presumably this is due to bremsstrahlung generation in the acrylic - whatever it is, it certainly isn't very penetrating (it won't go through a finger).
But maybe someone here has a better idea?