Re: Cross Post: Radioactivity in Watches? -Reply

["USHINO, TOSH" <ushinot@songs.sce.com>]

     In my first job at a small manufacturing company, we used beryllium 
     discs about the size of a half-dollar coin with about 300 Ci of 
     tritium gas diffused into them. Very soft x-ray (E.Ave ~2 - 4 keV, I 
     think) emitted from it was used for x-ray flurescence analysis (Note: 
     it was not encapsulated).  H-3 sources were mounted next to tiny 
     encapsulated Am-241 sources used for energy calibration.  We had to do 
     wipe tests on the Am-241 sources but not required to do that on the 
     H-3 sources.  After a while, tritium-containing beryllium will began 
     to flake off... played havoc with wipe testing Am-241 sources because 
     wipe testing was done using a pancake GM probe.

     Tosh Ushino
     SONGS


______________________________ Reply Separator _________________________________
Subject: Cross Post:  Radioactivity in Watches? -Reply
Author:  radsafe@romulus.ehs.uiuc.edu at internet
Date:    4/25/95 4:07 PM


Gosh this is a fun topic. 
     
Some posts have suggested tritium as a possibility. Are we saying 
that a low energy gamma probe (or the GMs referred to) are picking up 
bremsstrahlung from tritium in a watch? I tried out my LEG probe on a 
ca 3 to 6 Ci tritium exit sign to no avail. Same result with a 
tritium illuminated compass and a tritium illuminated sight for an 
M-16. The LEG (and a GM) had no problem seeing Pm though. 
     
There are circumstances where a GM can pick up H-3 if present in very 
high amounts and not encapsulated - but in a watch?. Has anyone 
experience to the contrary with known (vs speculated) tritium 
sources?
     
BTW  I've been looking for an antique chamber pot with a 
radioluminescent lid, and a related item, a black (uranium) ceramic 
commode. These things were really built. If you happen to find one, 
let me know. Thanks. 
     
Gotta go
     
Paul Frame