Final answer:
Leakage radiation refers to unwanted escape of radiation, like microwaves or ionizing radiation; safety levels depend on the type of radiation and the distance from the source. Microwaves are considered safe at intensities of 1.00 W/m², while for ionizing radiation, proper shielding and calculations using quality factors are necessary to determine safe exposure limits.
Step-by-step explanation:
Leakage radiation refers to any unwanted escape of radiation, such as microwaves from a radar unit or potentially harmful ionizing radiation from medical or industrial equipment. The question pertains to the maximum permissible levels of leakage and how to quantify safety distances or intensities related to exposure. For ionizing radiation, limits are typically expressed in milliroentgens (mR) and distance is a critical factor in determining safe exposure levels.
In terms of microwaves, a safe intensity for human exposure is considered to be 1.00 W/m². If a radar unit leaks 10.0 W of microwaves, the power is assumed to spread uniformly over the surface of a sphere. Using this model, to find the safe distance, one can use the formula for the surface area of a sphere (4πr²), where r is the radius. To calculate r, set the intensity (power per unit area) equal to the maximum safe intensity. The electric field strength at a given intensity can be found from the relationship between intensity and electric field in electromagnetic waves.
For ionizing radiation, such as alpha, beta, and gamma rays, it is crucial to use proper shielding and maintain safe distances to reduce exposure. The effectiveness of shielding can vary with different types of radiation. For example, several centimeters of lead are needed to significantly reduce the intensity of gamma rays, whereas alpha particles can be stopped by just a few millimeters of material. The radiobiological effectiveness (RBE), also known as the quality factor (QF), must be considered when assessing dose equivalency, as some forms of radiation are more damaging biologically than others.