Final answer:
The secondary protective barrier is used to attenuate stray radiation, in accordance with radiation protection practices that involve shielding to reduce exposure.
Step-by-step explanation:
The barrier used to attenuate stray radiation is known as the secondary protective barrier. It is distinct from other types of barriers, such as the x-ray tube housing which contains the radiation source and the primary protective barrier which prevents direct, primary radiation from escaping into adjacent areas.
The secondary protective barrier is specifically designed to protect against scattered or secondary radiation which might bounce off from other structures or objects during an x-ray procedure. This protective measure aligns with the principles of radiation protection which suggest keeping shielding between you and the source of radiation to reduce exposure. More shielding equates to less exposure to stray radiation.