[ RadSafe ] Ba 133 dose calibrator accuracy

Michael Bohan mike.bohan at yale.edu
Tue Apr 10 17:16:42 CDT 2007


Hello Gary and RadSafers,

Of course, I'm assuming that you have zero'ed and background corrected 
your dose calibrator first...

The next most likely reason is your decay correction of the Ba-133 
source.  Some references do not give the correct half-life for Ba-133.  
Currently, NIST lists the half-life for Ba-133 of 3854.7+/- 2.8 days 
(10.55 years).  Some references list 7.2 years (the Old Rad. Health 
Handbook).

http://physics.nist.gov/PhysRefData/Halflife/halflife.html

Also, if you have a very old Ba-133 reference source there may be some 
contaminant(s) that may be adding to the expected value.

Regards,

Mike Bohan, RSO
Yale-New Haven Hospital
Radiological Physics
20 York St. - WWW 204
New Haven, CT 06510
Tele: (203) 688-2950
Fax: (203) 688-8682
Email: mike.bohan at yale.edu

This message originates from Yale New Haven Health System. The 
information contained in this message may be privileged and 
confidential. If you are the intended recipient, you must maintain this 
message in a secure and confidential manner. If you are not the 
intended recipient, please notify the sender immediately and destroy 
this message. Thank you.




More information about the RadSafe mailing list