What is the quality factor for X-ray, gamma, or beta radiation?

What is the quality factor for X-ray, gamma, or beta radiation?

• A. 2
• B. 3
• C. 5
• D. 1

Answer: (D)

Quality factor relates absorbed dose to biological effect and rises with how densely a radiation ionizes tissue (LET). X-ray, gamma, and beta radiation are low-LET, depositing energy sparsely, so their biological effectiveness per unit energy is similar to that of a gray, which is defined as a quality factor of 1. Therefore, the quality factor for these radiations is 1, meaning the equivalent dose in sieverts equals the absorbed dose in grays. In contrast, high-LET radiations like alpha particles have a much higher quality factor due to dense ionization.

Quality factor relates absorbed dose to biological effect and rises with how densely a radiation ionizes tissue (LET). X-ray, gamma, and beta radiation are low-LET, depositing energy sparsely, so their biological effectiveness per unit energy is similar to that of a gray, which is defined as a quality factor of 1. Therefore, the quality factor for these radiations is 1, meaning the equivalent dose in sieverts equals the absorbed dose in grays. In contrast, high-LET radiations like alpha particles have a much higher quality factor due to dense ionization.