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. |
|
|
|
|
|
|
|
|
References Radium Chemical Company catalog. Radium Radon. No date. ca. 1940s, 1950s. Union Miniere catalog. Radium, Radon, Radium D. No date. |
|
