| 摘要 |
The invention deals with computerized tomography based on the object imaging with small angle scattered radiation. The registration of the scattering is made in ultra-small angles: from 0 to 1 degree relatively to the direction of the falling beam. Several schemes allowing to perform the registration of coherent scattering in the mentioned angles are suggested. The fan-shaped low-diverging beams formed by the collimator are directed to the object. In one of the variants of the device it is suggested to use a special spatial filter situated beyond the object for the separation of the radiation scattered on small angles; this filter represents a collimator-like structure, in which radiation-transparent areas of the collimator are overlapped by opaque areas of the filter. With this in the absence of the object the radiation does not pass on the space-sensitive detector situated beyond the filter. Being installed between the collimator and the spatial filter, the detector registers the scattering of the radiation on small angles. In order to register the radiation passed through the object in the direction of the primary beam, the detective elements are installed on opaque areas of the filter. It allows to obtain, besides a tomogram in the scattered radiation, tomographic images by the absorbed radiation. In another variant of the device the areas of the filter overlapping the transparent areas of the collimator, are made partially absorbing the radiation passed through the object along the direction of the falling beams, and decreasing it to the level of intensity of the scattered radiation. One of the suggested schemes allows to determine the object's scattering function within the limits of the primary beam. Based on the data of scattering obtained for different views of the object relatively to the system "source - collimator - detector" it is possible to restore the tomographic image of the object. 3 independent points of formulae, 9 figs. <IMAGE> |
