The reduction of energy of the x-ray photon as it passes through material is termed as:

The term that refers to the reduction of energy of the x-ray photon as it passes through material is "attenuation." Attenuation encompasses both absorption and scattering processes that contribute to the overall decrease in the intensity of the x-ray beam as it interacts with matter. When x-ray photons enter a material, some of them are absorbed by the atoms, while others may be scattered in different directions. Both of these interactions result in a loss of energy and intensity of the original x-ray beam.

In the context of imaging and radiation physics, understanding attenuation is crucial. It is a primary concept that impacts image quality and diagnostic effectiveness, as various tissues and materials attenuate x-rays differently, leading to variations in contrast on the resulting images. This variation is essential for differentiating structures within the body during imaging procedures.