Figure 14. Shapes of lead-lined control-screens.
(2) Modular operator protective screens consist of various sized prefabricated opaque shielding panels,
transparent viewing panels, and assembly hardware. To provide continuity of shielding, the panels are installed using steel
coupling or end brackets that are lead-lined on the surface of the x-ray source. See figure 15 for details.
h. Voids in protective barriers. Openings in protective barriers for doors, windows, ventilation ducts, conduits,
pipes, etc., may require radiation baffles to ensure that the required degree of overall protection is maintained. Two types
of protective barriers are used to guard against radiation: primary protective barriers and secondary protective barriers.
All walls, doors, floors, and ceiling areas exposed to the useful (primary) beam shall be considered primary protective
barriers. All areas exposed to the stray radiation shall be considered secondary protective barriers. Whenever possible,
the opening should be located in a secondary barrier where the required shielding thickness is less. The design of the
baffles will depend upon a number of factors. These include; energy of radiation, orientation and field size of useful beam,
size and location of opening in the protective barrier, and geometrical relationship between radiation source and opening.