| 摘要 |
PURPOSE: To detect a low-density substance that is closed, for example, in a bag or a container, etc., in real time by irradiating an object with gamma rays with a predetermined minimum energy for generating the X-ray fluorescence of an element. CONSTITUTION: A gamma ray source 16 generates conical beams of gamma rays that hit against a container 14 and a substance 12 in it and are indicated by an arrow 18. Gamma rays generate the interference scattering of X rays by the atom of elements that the container 14 and the substance 12 have. X rays generated by the elements have an energy and a wavelength that are peculiar to the elements. The X rays that are indicated by a wave line 20 change wavelength or change energy from a relatively low energy to a relatively high energy. For example, fluorescent X rays from a plastic bomb or a drum have a relatively low energy with in a range of several KeV. However, a nuclear explosive have a relatively high energy in the order of 100KeV. The X rays are detected by an X-ray detection device 22, thus detecting a low- density substance closed into the container in real time. |
