A radiographic test object for the LDR Selectron remote afterloading system

The authors took contact autoradiographs of loaded source trains as part of their monthly quality assurance programme for the Selectron LDR remote after-loading systems. To improve the resolution of these autoradiographs a simple test object was constructed, consisting of a multilayer sandwich of alternating sheets of lead (nominal thickness 2.00 mm) and cellulose acetate sheet (0.5 mm thick). This produced a set of individual slit collimators for each Selectron source position. (U.K.)