Moravian instruments, Inc., source: https://www.gxccd.com/art?id=395&lang=409, printed: 19.09.2024 9:00:14

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25.6.2012
G1 CCD All-sky Cameras on Pierre Auger Observatory
 Pierre Auger observatory was designed to capture traces of high-energy cosmic rays. While detection of low-to-middle energy cosmic rays is not a big problem, high-energy rays (1019 or 1020 eV) are very rare. This is why the whole observatory is spread over vast area of western Argentina's Mendoza Province. Two independent methods of particle detection are used. The first detects high energy particles through their interaction with water placed in surface detector tanks. The other technique tracks the development of air showers by observing ultraviolet light emitted high in the Earth's atmosphere. Grid of mirrors focus the UV light to photomultiplier tubes and here the G1 all-sky camera comes to help prevent degradation of these sensitive devices from various intensive light sources

Pierre Auger observatory became famous through the deployment of 1,600 water tanks over the Pampa Amarilla in western Argentina.

Water tank (left) and Cerenkov luminescence detector (right). Images courtesy of http://www.auger.org/

But as important for cosmic rays detection are telescopes, detecting ultra-violet light generated by high-energy particles traveling through Earth's atmosphere by speeds exceeding speed of light in the particular environment (not speed of light in vacuum, ability to do this is reserved only for neutrinos these days :-). This effect is called Cerenkov luminescence.

Example of background intensity from individual photomultiplier arrays

Example of background intensity from individual photomultiplier arrays

Photomultiplier tubes, detecting the UV luminescence, degrade when exposed to intensive light. This is why a group from Palacky University Olomouc designed a system based on G1 CCD cameras equipped with fish-eye lenses, monitoring entire sky when the Cerenkov telescopes are observing. When some source of bright light occurs within field of view, particular photomultiplier tubes are covered to protect them from degradation.

Example of all-sky image above the Coihueco telescope, Argentina

Example of all-sky image above the Coihueco telescope, Argentina

G1 cameras, rugged in the water-proof case, are mounted on the Coihueco and Los Leones Cerenkov light detection telescopes.

Los Leones observatory building. Images courtesy of http://www.auger.org/

Los Leones observatory building. Images courtesy of http://www.auger.org/

G1 all-sky camera in waterproof case and the associated electronics box on the Los Leones observatory

G1 all-sky camera in waterproof case and the associated electronics box on the Los Leones observatory

The whole application was developed by Research Center for Optics of Palacky University Olomouc. Images courtesy of Dusan Mandat.