Telescope Array Project: Difference between revisions

Revision as of 01:04, 21 March 2013

Revision as of 12:58, 17 June 2013

Line 1:

[[Image:Taplogo.png|right|200px|Telescope Array Project logo]]

The '''Telescope Array project''' is an international collaboration involving research and educational institutions in Japan, The United States, Russia, South Korea, and Belgium.<ref name=Tokuno>{{cite journal|last=Tokuno|first=H.|coauthors=et al|title=New air fluorescence detectors employed in the Telescope Array experiment|journal=Nuclear Instruments and Methods in Physics Research A|date=21 February 2012|volume=676|pages=54-65|doi=10.1016/j.nima.2012.02.044}}</ref> The experiment is designed to observe air showers induced by [[ultra-high-energy cosmic ray]] using a combination of ground array and air-fluorescence techniques. It is located in the high desert in [[Millard County, Utah|Millard County]], [[Utah]] (USA) at about {{convert|1400|m|ft|sp=us}} above sea level.

==Overview==

The Telescope Array observatory is a hybrid detector system consisting of both an array of 507 scintillation surface detectors (SD) which measure the distribution of charged particles at the Earth's surface, and three fluorescence stations which observe the night sky above the SD array.<ref name="AbuZayyad2012">T. AbuZayyad et al., "[http://www.telescopearray.org/media/TA_papers/1-s2.0-S0168900212005931-main.pdf The surface detector array of the Telescope Array experiment]" Nuclear Instruments and Methods in Physics Research Section A: (2012) vol. 689</ref> Each fluorescence station is also accompanied by a LIDAR system for atmospheric monitoring.<ref name="chikawaICRC">M. Chikawa et al., Proceedings of 29th [[International Cosmic Ray Conference|ICRC]] (2005) 137</ref> The SD array is much like that of the [[AGASA]] group, but covers an area that is nine times larger. The hybrid setup of the Telescope Array project allows for simultaneous observation of both the longitudinal development and the lateral distribution of the air showers.

At the center of the ground array is the Central Laser Facility which is used for atmospheric monitoring and calibrations.

==CosmicSurface Ray Centerdetector==

The surface detectors that make up the ground array are activated when ionizing particles from an extensive air shower pass through them. When these particles pass through the plastic scintillator within the detector, it induces photo electrons which are then gathered by wavelength-shifting fibers and sent to a photomultiplier tube. The electronic components within the detectors then filter the results, giving the detectors comparable accuracy to the AGASA experiment.<ref name=Kawai2008>{{cite journal|last=Kawai|first=H|coauthors=et al|title=Telescope Array Experiment|journal=Nuclear Physics B (Proceedings Supplements)|year=2008|pages=220-226|doi=10.1016/j.nuclphysbps.2007.11.002}}</ref>

The Lon and Mary Watson Millard County Cosmic Ray Center was dedicated on March 20, 2006.<ref>Draper, Dean (March 22, 2006). "Cosmic ray center dedicated". Millard County Chronicle Progress</ref> The center is located at 648 West Mail Street in Delta - the seat of Millard County. The building serves as a headquarters and data processing center for the Telescope Array Project.

In October of 2011, a new visitor center was opened at the Cosmic Ray Center. It features displays about the history of cosmic ray research in Utah and about the Telescope Array, which is spread across the desert west of Delta. The center also includes a display about the nearby Topaz internment camp, where U.S. citizens of Japanese descent were imprisoned during World War II.

==Surface detector==

The surface detectors are evenly distributed across a 762&nbsp;km² grid array with 1.2&nbsp;km between each unit. Each surface detector has an assembled weight of 250&nbsp;kg and consists of a power supply, two layers of scintillation detectors and electronics. Power is generated by a 120W solar panel and stored in a sealed lead-acid battery. The system has the capacity to operate for one week in complete darkness. Each scintillation detector layer is made of extruded plastic scintillator that is 1.2&nbsp;cm thick and has an area of 3m². The photo multiplier tube is connected to the scintillator via 96 wavelength-shifting fibers.

Line 18 ⟶ 15:

[[Image:BRM-FD-open.jpg|thumb|200px|right|a view of the Black Rock Mesa FD site with the doors open]]

{{GeoGroup}}

The Telescope Array has three fluorescence detector (FD) telescope stations. As in the previous Fly's Eye and [[High Resolution Fly's Eye Cosmic Ray Detector|High Resolution Fly's Eye]] (HiRes) experiments, these detectors work by measuring the air fluorescence light emitted by an [[Air shower (physics)|extensive air shower]]. Each FD telescope consists of a primary mirror (made up of 18 smaller hexagonal mirror segments) and a camera. The cameras are made up of 256 PMTs (photomultiplier tubes) which are sensitive to the ultra violet light generated by a cosmic ray air shower.<ref name=Tokuno />

The Telescope Array has three fluorescence telescope stations. The stations are located on a triangle about 35&nbsp;km apart from one another. Each station has 12-14 telescopes viewing the range from 3 to 33 degrees in elevation. The three sites are named ''Black Rock Mesa'' (BRM), ''Long Ridge'' (LR), and ''Middle Drum'' (MD).<ref>http://www.telescopearray.org/index.php/research/clear-sky-clocks</ref>

The Telescope Array has three fluorescence telescope stations. The stations are located on a triangle about 35&nbsp;km apart from one another. Each station has 12-14 telescopes viewing the range from 3 to 33 degrees in elevation. The three sites are named ''Black Rock Mesa'' (BRM), ''Long Ridge'' (LR), and ''Middle Drum'' (MD).<ref>http://www.telescopearray.org/index.php/research/clear-sky-clocks</ref> By combining the data from the three sites, it is possible to determine the primary energy, the arrival direction, and the maximum

Each telescope is instrumented with a camera made up of 256 PMTs (photomultiplier tubes) which are sensitive to ultra violet light

generatedpoint byof alongitudinal cosmicdevelopment rayfor an air shower.<ref name=Tokuno />

Line 60 ⟶ 57:

|}

==Cosmic Ray Center==

The Lon and Mary Watson Millard County Cosmic Ray Center was dedicated on March 20, 2006.<ref>Draper, Dean (March 22, 2006). "Cosmic ray center dedicated". Millard County Chronicle Progress</ref> The center is located at 648 West Mail Street in Delta - the seat of Millard County. The building serves as a headquarters and data processing center for the Telescope Array Project.

In October of 2011, a new visitor center was opened at the Cosmic Ray Center. It features displays about the history of cosmic ray research in Utah and about the Telescope Array, which is spread across the desert west of Delta. The center also includes a display about the nearby Topaz internment camp, where U.S. citizens of Japanese descent were imprisoned during World War II.

==TALE==