Surface Detector
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.
The surface detectors are evenly distributed across a 762 km2 grid array with 1.2 km between each unit. Each surface detector has an assembled weight of 250 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 cm thick and has an area of 3m2. The photo multiplier tube is connected to the scintillator via 96 wavelength-shifting fibers.
Read more about this topic: Telescope Array Project
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