A Theoretical Analysis of the Operation of Flying Spot and Camera Tube Microscopes in the Ultraviolet

Abstract
The minimum specimen exposure at television scanning rates required to yield pictures with acceptable signal-to-noise ratio and the best resolution optically attainable is computed for flying-spot, image-orthicon, and vidicon television microscopes for the ultraviolet. This exposure is found to be slightly less for the flying-spot microscope than for the image-orthicon microscope. For microscopes employing experimental ultraviolet-sensitive vidicons with optimal quantum efficiency, the exposure is greater than for the image-orthicon microscope by a factor of 2, and it may be greater by a factor up to 10 for vidicon microscopes with less favorable characteristics. Picture lag is absent in flying-spot microscopes and is not a serious consideration in image-orthicon microscopes, but may limit the permissible motion in the field of an ultraviolet vidicon microscope. On the other hand, the attainable radiance of flying-spot tube screens limits the usefulness of the flying-spot microscope in high-resolution studies, particularly when examination with sharply defined spectral bands is desired. No similar limitation exists for the image-orthicon and vidicon microscopes.

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