Halation-prevention filter, image analysis device equipped with said halation-prevention filter, and diffraction pattern intensity analysis method and diffraction pattern intensity correction program that use said halation-prevention filter

An image analysis device comprising:

• a fluorescent screen for creating a diffraction pattern that results from reflection high-energy electron diffraction;
• a photoreceptor for optically acquiring the diffraction pattern that appears on the fluorescent screen;
• and
• a halation-prevention filter for location along a light path connecting the fluorescent screen and the photoreceptor, in which a transmittance of the visible light transmitted through the filter is minimum at a center of the filter and increases with a distance from the center.

A diffraction pattern intensity analysis method used to analyze intensity of visible light emitted from a diffraction pattern of a fluorescent screen as a result of reflection high-energy electron diffraction, comprising the steps of:

• using a photoreceptor to measure the intensity of the diffraction pattern that appears on the fluorescent screen, via a halation-prevention filter with a transmittance which is minimum at a filter center and increases with distance from the filter center;
• based on a result of the measurement, obtaining a rate of decrease in the intensity of the visible light transmitted through the filter;
• and
• correcting the diffraction pattern intensity measured by the photoreceptor, based on the decrease rate.

A diffraction pattern intensity correction program for use with an image analysis device having a fluorescent screen for creating a diffraction pattern that results from reflection high-energy electron diffraction, a photoreceptor for optically acquiring the diffraction pattern that appears on the fluorescent screen, and a halation-prevention filter for location along a light path connecting the fluorescent screen and the photoreceptor, in which a transmittance of the visible light transmitted through the filter is minimum at a center of the filter and increases with a distance from the center, the program comprising:

• a measured intensity storage means for storing an intensity of visible light emitted from the diffraction pattern on the fluorescent screen as a result of reflection high-energy electron diffraction, passed through the halation-prevention filter and detected by the photoreceptor means;
• an intensity decrease rate storage means for storing a rate of decrease in the intensity of the visible light transmitted through the halation-prevention filter;
• and
• a corrected-intensity computation means for computing a corrected intensity of the diffraction pattern by correcting the intensity stored by the measured intensity storage means, based on the decrease rate stored by the intensity decrease rate storage means.