Fading in TLD

[tracyjw@nist.gov]

I am setting up an environmental monitoring program using TLD.  I am using a Harshaw 6600 TLD 

reader (hot gas heating) and TLD 600 and TLD 700.  My TTP uses a 2 second preheat at 100 C.  I 

plan to use a 3 month monitoring period and a reader anneal.  In checking the literature I see 

typical fading corrections of 25 - 30 % for a 90 day period.  While I can measure the fading and 

provide a correction factor I would prefer to reduce the fading.

I am investigating the use of procedures (in addition to the reader anneal) that help reduce the 

fading.  Some of the procedures I have seen in the literature are

1)  24  hour pre-irradiation anneal
2)  2 hour pre-irradiation anneal
3)  Reader anneal 10 sec at 130 C
4)  Glow curve deconvolution

I'm looking for advice and information from anyone with a similar system who uses these or other 

procedures.  I'm interested in what procedure(s) you use in addition to a reader anneal, your 

typical fading correction factors, drawbacks/pitfalls (reduced sensitivity?) with your 

method(s), and any information you feel might be helpful.

You can reach me at the email address listed below.

Jim Tracy
james.tracy@nist.gov

All views are my own.  My employer did not review/approve this message.