What is meant by the term “secondary radiation” in radiation protection?

The term “secondary radiation” refers to radiation that is emitted by materials that have been irradiated. This occurs when primary radiation interacts with matter, causing the material to emit its own radiation. For example, when X-rays hit a target, the target material may absorb some of this radiation and re-emit it as characteristic radiation or as scattered radiation.

This concept is important in radiation protection because it emphasizes the need to account for all sources of radiation exposure, not just the direct or primary radiation from the source. Understanding secondary radiation helps radiation safety personnel develop effective safety protocols to minimize exposure to both primary and secondary radiation, ensuring a safer working environment.

In contrast to this, primary radiation is emitted directly from a radiation source, while scattered radiation can refer to a specific aspect where primary radiation is deflected rather than emitted from an irradiated material. The absorption of radiation by protective equipment is a separate consideration in radiation protection strategies, which also emphasizes the importance of proper shielding to reduce exposure from all types of radiation, including both primary and secondary.