Final answer:
The primary radiation barrier in fluoroscopic installations is the image intensifier assembly, which enhances image brightness and reduces the need for high radiation doses. Additional radiation protection measures include lead aprons, shielding, and adhering to principles like minimizing exposure time and maximizing distance from the source.
Step-by-step explanation:
The primary radiation barrier in the fluoroscopic installations is considered to be the image intensifier assembly. This component intensifies the image seen on the fluoroscope by increasing the brightness of the image, which allows for lower radiation doses to be used. By reducing the need for high radiation doses, the image intensifier serves as a primary barrier. Radiation protection also includes additional measures such as using lead aprons, shielding around the x-ray tube, and principles like minimizing exposure time, maximizing distance from the radiation source, and utilizing adequate shielding.
For instance, when taking dental x-rays, a lead apron is placed over the patient and additional shielding is used to restrict exposure to other tissues. Technicians also protect themselves by standing behind lead-lined doors or using lead glass windows to reduce occupational exposure. In nuclear reactors, multiple layers of shielding are employed, such as the reactor vessel itself, a main shield of high-density concrete, and a personnel shield to protect operators from different types of radiation.