The Telescope Array (TA) is the largest cosmic ray observatory in the northern hemisphere. The experiment is a collaboration between the University of Utah and universities in Japan, Korea, Russia, and Belgium. The Telescope Array studies particle showers generated when Ultra High Energy Cosmic Rays (UHECR) interact with the Earth's atmosphere. UHECR's are cosmic ray particles with energies greater than 1018 eV. That is 100,000 times more energetic than any particles produced in a laboratory on Earth.
The flux of UHECRs is extremely low, which means that our detectors must search over a very large area in order to make observations. TA encompasses an area of ~750 km2 in central Utah and uses a combination of air-fluorescence telescopes and scintillator detectors to measure the particle showers. The telescopes make measurements of the particle shower as it traverses the atmosphere, while the scintillators sample the footprint of the shower when it reaches the Earth’s surface.
The observations which TA makes tell us about the initial cosmic ray particle which induced the shower. Specifically we measure the energies of these particles, their chemical composition, and their sources. TA has been taking data since 2007, and has made some preliminary measurements. As more time passes, and more information can be gathered, we will make some of the most accurate measurements in the field.
As a graduate student working for TA, it is important that I learn as much as possible about the different detectors used in the experiment. The Scintillator Surface Array is made up of 507 detectors. These detectors are built at the Akeno Observatory, located in the Japanese Alps. I met with collaborators and helped to put together some of these detectors last summer. I learned about the scintillating material and optical fibers that are used to measure the charged particles from the air shower. I even managed to do some sight seeing in the area before heading back to the U.S. Once those detectors are shipped to Utah, I will help with final assembly and testing before they are deployed in the desert.