7. Radiography and related techniques

X-rays are used to examine the structure or internal health of an object by passing very short-wave electromagnetic radiation (X-rays or γ-rays) through it and collecting the beam's intensity modulations in the form of an image on a suitable receiver - a film in most cases, as illustrated in figure 23 . By the same token, images can be obtained using particles other than photons, enabling techniques such as neutronography, which will also be discussed in this section.