3M Line Source (1963) 

This is a dummy line source manufactured in 1963 by 3M (Minnesota Mining and Manufacturing).  An actual source would have contained up to 200 mCi of Cs-137. The cesium is incorporated into microspheres (30 to 200 micrometers) that are doubly encapsulated in two very thin stainless steel tubes. The tubes are fixed by epoxy in a 1" long slot of the bottom of the source disk (see photo below left). The latter is 1 1/2" in  diameter and 3/16" thick.  The intent is that it serve as a beta source, possibly for thickness or backscatter gauges. It is also possible that it could be used as a static eliminator. 

Reference

Registry of Radioactive Sealed Sources and Devices Safety Evaluation of Sealed Source form. August 7, 1964.

Radioactive Sources                    Museum Directory

Last updated: 05/10/11
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