Search for persons

X-rays and gamma-rays are used to detect hidden persons in vehicles, containers, and railway wagons. They are produced with accelerators, X-ray tubes, cobalt 60 and caesium 137. Fan beams adjusted to a line of digital detectors produce the image. The resolution is sufficient to recognise a human being. The recognition of persons with transmission images is limited by superimposition; backscatter imaging produces clearer images but of one single layer only. The future will bring new applications of search for persons with X-rays. Crimes and terrorist attacks will induce added demand for security, where search with X-rays and gamma-rays will keep its important role or even increase it.