Get a large magnetic field too close to the PMT and the count rate will likely 
go to zero on that detector.  Seen this with PMT based instruments near large 
magnetic fields (e.g., heavy equipment hydraulic rams, large vehicle 
alternators, large magnets, etc.)

Suggest testing this with the magnet(s) you want to release with a source in 
the chamber.  You will have to override the door closure interlock so you can 
move the magnet around.  It should be fairly straight forward to find a 
location in the chamber that is allows for surveying the magnet without an 
adverse effect on the instrument.

David Brehm
Sr. Radiological Engineer
Radiation Protection – Fort Calhoun Station
Omaha Public Power District
9610 Power Lane, Blair, NE 68008
Office: 402.533.7582
Cellular: 402.237.9840<>

From: Macho, Michael []
Sent: Thursday, February 22, 2018 11:20 AM
To:; '' <>
Subject: [powernet] FW: Had a question on TEMs, SAM 11/12

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Wanted to see what others have experienced when placing larger and more 
powerful magnets into TEMs.

From: Palatine, Rich []
Sent: Thursday, February 22, 2018 10:13 AM
To: Macho, Michael 
Subject: Re: Had a question on TEMs, SAM 11/12



Large magnets don't affect the SAM detectors.  We have it seen anything like 
that I the 20+ years of the SAMs.


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On Feb 22, 2018, at 8:28 AM, Macho, Michael 
<<>> wrote:
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Had a question that I hope you know the answer or someone that can give me an 
answer.  The question is related to the nuclear promise procedures.

Do large/powerful magnets damage the SAM detectors?

I should be sending two of the RADEYE NLs to Thermo for calibration sometime in 
the near future.  I didn’t get good results for my verification inside the 
reactor building at power so I need to redo my verification of the correction 

Mike Macho

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