Theoretical bases of hypothetical sphere-electrode detectors and practical near-sphere-electrode (semisphere-electrode and near-semisphere-electrode) detectors

Abstract

In this work, one-dimensional (1D) modeling and simulations of the electric and weighting fields will be systematically carried out for hypothetical sphere-electrode detectors. Exact 1D solutions are obtained for electric and weighting fields in these detectors. Although it is impossible to realize hypothetical sphere-electrode detectors with current technologies, the theoretical work and results on them are good bases for their offspring—practical semi-sphere-electrodes (semisph-electrode) and near-semisph-electrode detectors. The great reduction in full depletion voltage and small capacitance in semisph-electrode and near-semisph-electrode detectors make them very good for applications in photon sciences (x-ray) and safeguard and homeland security (hard x-ray and gamma-ray). A practical novel structure of the three-dimensional (3D) trench electrode detector, namely a novel semisph-electrode silicon detector has been proposed as a practical example. The novel detector has a semispherical shell electrode created in a cuboidal unit cell. It will overcome the traditional 3D-electrode detector deficiencies in electrical performance such as the asymmetrical electric field distribution. Through a computer-aided design tool, 3D modeling and electrical characteristics, simulation of a semispherical electrode silicon detector has been obtained, such as electric field distributions, electron concentration distribution, and full depletion voltage