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 [email protected]<mailto:[email protected]> From: Macho, Michael [mailto:[email protected]] Sent: Thursday, February 22, 2018 11:20 AM To: [email protected]; '[email protected]' <[email protected]> Subject: [powernet] FW: Had a question on TEMs, SAM 11/12 Phishing = #1 threat to OPPD Is this a phishing email? - Look again! This email is from [email protected]<mailto:[email protected]> - do you know them? Use the "Report it" button if you think this is a phishing email. ________________________________ Wanted to see what others have experienced when placing larger and more powerful magnets into TEMs. From: Palatine, Rich [mailto:[email protected]] Sent: Thursday, February 22, 2018 10:13 AM To: Macho, Michael <[email protected]<mailto:[email protected]>> Subject: Re: Had a question on TEMs, SAM 11/12 EXTERNAL EMAIL Mike, Large magnets don't affect the SAM detectors. We have it seen anything like that I the 20+ years of the SAMs. Rich Sent from my iPhone On Feb 22, 2018, at 8:28 AM, Macho, Michael <[email protected]<mailto:[email protected]>> wrote: CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. Rich, 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 factor. Mike Macho 817-559-1997
