What is the process called when x-rays are absorbed by matter?

The process in which x-rays are absorbed by matter is known as attenuation. Attenuation refers to the reduction in the intensity of x-rays as they pass through different materials. This process is essential in medical imaging, as it allows for the differentiation of various tissues in the body based on their density and composition.

For instance, dense materials like bone absorb x-rays more effectively than softer tissues, which results in a contrast that is critical for creating clear images on x-ray films or digital detectors. By understanding how different substances attenuate x-rays, imaging professionals can interpret x-ray films accurately and make informed decisions regarding patient care.

In contrast, the other terms listed describe different phenomena: radiation broadly refers to energy emitted in various forms, like x-rays themselves; refraction involves the bending of light as it passes through different media, and diffraction describes the behavior of waves when they encounter obstacles or openings. Therefore, attenuation accurately captures the specific interaction of x-rays with matter being discussed in the question.