Radium Plaque (ca. 1920s - 1940s)

Note: this is not in the ORAU Collection but is shown for informational purposes

The most common radium plaques were square but circular and oval ones were also available.  The plaques might be covered with a thin layer (e.g., 0.1 mm) of monel metal, lead, silver or other filtration.



       Plaque activities were expressed as follows:

           Double strength        10.0  mg Ra-226/cm2

           Full strength                5.0  mg Ra-226/cm2

           Half strength                2.5  mg Ra-226/cm2

           Quarter strength          1.25 mg Ra-226/cm2

                  Typical sizes were as follows:

                                                   Double strength    1 cm2, 2 cm2

                                                    Full strength        1 cm2, 2 cm2, 4 cm2
                                                   Half strength        2 cm2, 4 cm2, 8 cm2

The most common type of plaque would be the 4 cm2 (2 cm x 2 cm) half strength version, i.e., 10 mg Ra-226.

Radium plaques might be made of monel metal, enamel or brass. Often manipulated with a handle/applicator similar to that in the following images.


Radium Chemical Company catalog. Radium Radon. No date. ca. 1940s, 1950s.

Union Miniere catalog. Radium, Radon, Radium D. No date.

Brachytherapy                Museum Directory

Last updated: 01/20/09
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