Dose measurement in the TEM and STEM
| Autor: | Ray F. Egerton |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Physics Energy loss Inelastic collision 02 engineering and technology Electron 021001 nanoscience & nanotechnology 01 natural sciences Fluence Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Computational physics 0103 physical sciences Radiation damage Dosimetry Stopping power (particle radiation) 0210 nano-technology Instrumentation Current density |
| Zdroj: | Ultramicroscopy. 229 |
| ISSN: | 1879-2723 |
| Popis: | Practical aspects of dosimetry are considered, including the measurement of electron-beam current and current density. Complications that arise in the case of a focused probe or a STEM image are discussed and solutions proposed. Advantages of expressing the radiation dose in Grays are listed and a simple formula given for converting electron fluence to Gray units, based on a near constancy of the stopping power per atomic electron. Comparisons with stopping-power calculations and EELS measurements suggest that this formula is accurate to within 5%. Based on the stopping power formula, a new way of measuring the local mass-thickness of light-element specimens is proposed. The average energy loss per inelastic collision is shown to be higher than previous expectations. |
| Databáze: | OpenAIRE |
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