Polychromatic MTF of electrostatic point symmetric electron lenses
Abstract
The performance of electron imaging devices with image inverting electrostatic lenses as focusing elements is modeled analytically. Consideration is given to moonlight in AM1 and in starlight conditions. The modulation transfer function (MTF) is calculated for an electron lens with a polyenergetic electron emitter photocathode and a statistical angular distribution of photoelectrons following a Lambertian curve. Attention is given to the transverse focusing error and the image current density, as well as to polychromatic irradiation conditions. Prediction comparisons were made for a tungsten 2870 K radiation source. It is found that the electron lens performs better with the reference radiation than with starlit and moonlit conditions, and that actual performance predictions necessitate calculation of the MTF in polychromatic conditions.
- Publication:
-
Applied Optics
- Pub Date:
- August 1983
- DOI:
- 10.1364/AO.22.002453
- Bibcode:
- 1983ApOpt..22.2453N
- Keywords:
-
- Electron Optics;
- Electrostatics;
- Imaging Techniques;
- Modulation Transfer Function;
- Performance Prediction;
- Image Converters;
- Image Intensifiers;
- Lens Design;
- Spectral Energy Distribution;
- Spectral Sensitivity;
- Electronics and Electrical Engineering;
- MODULATION TRANSFER FUNCTION;
- IMAGE INTENSIFIERS;
- IMAGE TUBES