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Mie scattering by a charged dielectric particle
R L Heinisch1, F X Bronold, H Fehske
1Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany.
Physical Review Letters
|February 2, 2013
Summary
Surplus electrons in dielectric particles shift infrared extinction resonances. This optical method can measure particle charge, enabling minimally invasive plasma probing.
Area of Science:
- Condensed Matter Physics
- Optical Spectroscopy
- Plasma Physics
Background:
- Dielectric particles exhibit anomalous light scattering due to transverse optical phonon resonances.
- Excess electrons influence particle polarizability through phonon-limited conductivity.
- Electron behavior depends on surface (negative electron affinity) or bulk (positive electron affinity) states.
Purpose of the Study:
- To investigate the impact of surplus electrons on light scattering anomalies in dielectric particles.
- To explore the relationship between electron concentration and optical resonance shifts.
- To establish an optical technique for measuring particle charge in plasma environments.
Main Methods:
- Theoretical analysis of dielectric function incorporating electron effects.
- Modeling of light scattering phenomena influenced by phonon-limited conductivity.
- Infrared spectroscopy to observe extinction resonance shifts.
Main Results:
- Surplus electrons cause a measurable shift in the extinction resonance frequency.
- The magnitude of the shift correlates with the number of excess electrons.
- This effect is observable for both surface and bulk electron accumulation.
Conclusions:
- Optical resonance shifts provide a sensitive method for quantifying excess electrons in dielectric particles.
- This technique offers a non-invasive approach to measure particle charge in plasmas.
- Potential applications include advanced plasma diagnostics and material characterization.
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