What is the zone board?

The plate zone is a flat, circular material of the material used to focus light or other electromagnetic waves, such as X -rays, using the principles of diffraction. They are often referred to as Fresnel Zone boards and are related to the Fresnel lens, which are named after the French engineer century, Augustin-Jean Fresnel, which studied the nature of optics. The effects of a diffraction grid with a zone plate or a fresnel lens have applications in photography, microscopy and holography of gamma as well as for potential space antenna systems.

zone plates use the principle of diffraction to bending wool or other energy, such as sound or quantum levels of neutrons and helium atoms, by bending their incidence because they have an impact on transparent and opaque media. This creates a level of constructive interference in light waves, where they focus behind the zone board, which can increase resolution for certain aspects of light or energy wave. For processing all electromagneticThe radiation that affects the surface in this way is the zone plate formed by concentric circles that alternate between reflective or opaque properties and transparent or light properties, giving it the appearance of the bull.

A special type of zone board where dark and light rings disappear into each other, creating a single focus that was used with gamma rays in the field of medical imaging holography. This idea is examined to depict regions around isotopes of trace isotopes introduced into the body in nuclear medicine. When a radioactive source illuminates the zone board, the board casts a shadow that can be seen on a photographic movie in a smaller size than a real source. This image precisely reflects the interference formula created by the zone plate in three dimensions and the photographed image can be more closely illuminated by a common light for image reconstruction and to explore the structure around isotopes in detail.

X -ray microscopy is one of the primary research arenas for the use of diffraction grilles such as zone plates. This is because traditional lenses, such as glass, reflect X -rays or only weakly diffuse them instead of their focus, due to their small size wavelength and zone plates must be designed on a nanometer scale to achieve the desired focusing effect. Usually the X -ray zone plate has a circular diameter of about 4 millimeters and the thickness of the zone between 50 and 300 nanometers. Such plates zone can focus down to the X -rays down to the resolution as fine as 10 nanometers or 10 billion. For comparison, a typical water molecule or H _{2 o has about 1 nanometer in diameter. This makes it possible to study biological materials, crystals and other atomic structures with a fine degree of optical degree.}

Using zone plates made of 1 million thick tungsten to capture X -rays with high highEnergy with energy levels up to 250,000 electron volts (250 keV) size, in space antenna systems it has been investigated from 1968 to 2003. Two zone plates were used in a tandem in one experiment, with a diameter of 2.4 centimeters containing 144 concentric zones, located 30 centimeters apart in the telescope. They showed a distinction between about 30 arches, without Arago instead of in the process of casting shadows for X -rays. Arago or Poisson spots are a typical energy point that appears in the shadow center of the Fresnel diffraction pattern, where there is a constructive intervention between energy wavelengths. Reflector antennas zone for spacecraft are considered to be a technological leap forward from the traditional parabolic antenna, which has much lower costs and weight, with high gain characteristics and efficiency for capturing up to 95% of incident radiation.