Abstract
A calculational model for level measurement based on Compton scattering of γ rays without a collimator has been developed and examined by computer simulations.
A source and a detector are set up at the same side against a measured object. In this geometry, the amount of scattered γ rays is in proportion to the solid angle Ω to the object from the source. Here an imaginary effective point is introduced and it should be located on the upper surface of a region in which incident γ rays are scattered. The count of scattered γ rays by the detector also has a proportional relationship with the solid angle θ to the detector from the effective point. Therefore the γ rays count is a function of both solid angles Ω and θ. These angles include parameters of levels, in another word, distances from the source to the object and from the effective point to the detector. As a result, the level calculation can be carried out in the use of the γ rays count.
As the example of results, relative errors between computer simulations and model calculations are within approximately 0.7% in the level range of 10-100 cm in the case that the density of the object is 1.00 g/cm3 and the distance from the source to the detector is 20 cm. The results can provide the possibility of level measurement with the proposed model.
