Re: crystal detector

[AndrewsJP@AOL.COM]

In a message dated 2/21/2002 12:34:50 PM Eastern Standard Time, Andrew.Buchan@ehs.ucsb.edu writes:



> I have a researcher who is using a NaI detector for data acquisition over
>
> a long period of time. Unfortunatly they are finding a significant temperature 
>
> related drift in their crystal and PM tube (both ludlum)and are looking for
>
> another detector set up preferably solid state. Any recommendations you have 
>
> would be appreciated. 


As an aside, if you spend as much time and effort and money keeping your NaI(Tl) detector and especially the PM tube temperature constant as you do for a solid state detector, you will have the same kind of stability for both.  Generally, the problem occurs from very slight dimensional changes in the PM tube itself, thus changing the gain in the early stages.  I have had success using foam and bubble pack to insulate the detector assembly where ambient temperature changes are a problem.  Good luck.


John Andrews

Knoxville, Tennessee