Detector, linear dielectric

The aim of ECT, therefore, is to reeonstruct the distribution of dielectric permittivity e(x,y), which corresponds to gas-solids distribution, from the capacitance measurements. It is worth pointing out, however, that the equation (2) is non-linear as it couples the dielectric permittivity distribution with the potential field, which results from that distribution. In simple terms, a change of permittivity in one place affects the electric field in the whole domain. This is unlike the nucleonic transmission tomography, where the introduction of a small object in the domain (see Figure 5) affects only the detectors in the objects shadow . This property of electrical field makes the reconstruction algorithms a much more challenging task than those... 

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