What technology uses radiation to scan passengers and luggage?

The backscatter personnel x-ray system is designed specifically to use low levels of ionizing radiation to create detailed images of the body and objects concealed under clothing. This technology works by emitting x-rays that scatter back to the detector when they hit dense materials, allowing for the visualization of items, such as weapons or contraband, that may be hidden on a person's body without physically searching them.

Backscatter systems are commonly used in security settings, particularly at airports, because they can quickly and effectively scan individuals while maintaining a balance between thoroughness and the privacy of passengers. This technology is critical in aviation security, where detecting concealed threats is essential for passenger safety.

In contrast, while the millimeter wave imaging system and computed tomography also use advanced scanning technologies, they operate on different principles—millimeter wave systems use radio frequency waves, and computed tomography typically involves x-ray imaging but is more commonly associated with scanned luggage rather than personnel. Explosive trace detection is focused on identifying powder residues from explosives and does not involve the scanning of passengers in the same way.