tritium detection

["Les Slaback, Health Physics" <SLABACK@micf.nist.gov>]

Being one of the furloughed federal employees I am late in adding to this       
discussion.  But that has never held me back, so ....                           
                                                                                
The only way you will detect tritium with a windowed detector is if you         
have enough tritium so you can see the bremsstrahlung.  We could easily         
see curie levels, and I suspect you could see 100's of mCi'sper window          
area.                                                                           
                                                                                
Several windowless monitors are on the market, and they work, albeit in very    
carefully selected situations, e.g., clean, flat, static free surfaces.  You    
also need a low background environment for adequate sensitivity.  These         
*** may *** be useable but check them out carefully for your application.       
                                                                                
If you have tritium in a chemical form with a low vapor point, then swipes      
counted on liquid scintillation is usually more than adequately sensitive       
for surface contamination checks.  Take care to check for chemiluminescent      
interferences [which is easy on modern units that store spectra].               
                                                                                
SLABACK@MICF.NIST.GOV  [NBSR Health Physics Group]                              
    ...a little risk, like a bit of spice, adds flavor to life                  
                                                                               
QUIT