Characterization of trapped charges distribution in terms of mirror plot curve
| Autor: | Imad H. Khaleel, Ali S. Mahdi, Hassan N. Al-Obaidi |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Physics
Surface (mathematics) business.industry Point particle Magnetic monopole Charge (physics) 02 engineering and technology Electron 021001 nanoscience & nanotechnology Method of image charges Space (mathematics) 01 natural sciences Binomial theorem Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials 010309 optics Optics 0103 physical sciences Atomic physics 0210 nano-technology business Instrumentation |
| Zdroj: | Ultramicroscopy. 184:12-16 |
| ISSN: | 0304-3991 |
| DOI: | 10.1016/j.ultramic.2017.08.001 |
| Popis: | Accumulation of charges (electrons) at the specimen surface in scanning electron microscope (SEM) lead to generate an electrostatic potential. By using the method of image charges, this potential is defined in the chamber's space of such apparatus. The deduced formula is expressed in terms a general volumetric distribution which proposed to be an infinitesimal spherical extension. With aid of a binomial theorem the defined potential is expanded to a multipolar form. Then resultant formula is adopted to modify a novel mirror plot equation so as to detect the real distribution of trapped charges. Simulation results reveal that trapped charges may take a various sort of arrangement such as monopole, quadruple and octuple. But existence of any of these arrangements alone may never be take place, rather are some a formations of a mix of them. Influence of each type of these profiles depends on the distance between the incident electron and surface of a sample. Result also shows that trapped charge's amount of trapped charges can refer to a threshold for failing of point charge approximation. |
| Databáze: | OpenAIRE |
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