The detecting module based on gallium arsenide detectors in digital mammography
Success in early breast cancer diagnostic depends on technical characteristics of detecting module. The most important is detector resolution. In this paper we represent quantum-sensitive detectors of X-rays based on GaAs for digital mammography systems. Electron/hole pairs created by radiation, which interact with the GaAs detectors, result current pulse at the detector output and specialist can see image immediately. Progress in development and investigation of a semiconductor material capable to provide reliable registration of single quanta of roentgen radiation. It is supposed to reduce patient radiation doze. At the same time, the system delivers high-quality images with resolution, contrast and clarity equal to film X-rays, or even better. Main advantages which can be achieved by using these detectors are analyzed.
THE DOSE AND IMAGE QUALITY IN MAMMOGRAPHY PRACTICE IN FINLAND
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Explicit solutions for N-dimensional Schrödinger equations with position-dependent mass
With the consideration of spherical symmetry for the potential and mass function, one-dimensional solutions of nonrelativistic Schrodinger equations with spatially varying effective mass are successfully extended to arbitrary dimensions within the frame of recently developed elegant nonperturbative technique, where the BenDaniel-Duke effective Hamiltonian in one dimension is assumed like the unperturbed piece, leading to well-known solutions, whereas the modification term due to possible use of other effective Hamiltonians in one dimension and, together with the corrections coming from the treatments in higher dimensions, are considered as an additional term like the perturbation. Application of the model and its generalization for the completeness are discussed.