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Construction
With the exception of Ra-226, Am-241 and Pb-210 sources, the
radioactive isotope is absorbed in an ion-exchange bead approximately
1mm in diameter. The bead is fixed inside a solid plastic
capsule 25mm in diameter and 3mm thick. The active bead is
visible, and located at the geometric centre of the source.
For Am-241 and Pb-210, the active component is in the form
of a ceramic bead.
For Ra-226, the ion exchange bead is sealed inside a glass
capillary tube before being fixed inside a 6 mm thick plastic
disc. This construction (drawing VZ-590) reduces the possibility
of release of radon gas from the decay of Ra-226. |
