Speaker
Dr
Toshihiro FUJII
(KICP University of Chicago, ICRR University of Tokyo)
Description
The Telescope Array (TA) experiment is the largest cosmic ray detector in the Northern Hemisphere. The TA surface detector (SD) array is deployed on a square grid of 1.2 km spacing, covering an effective area of 700 km^2. The TA SD is overlooked by three fluorescence detector (FD) stations: Black Rock Mesa (BRM), Long Ridge (LR), and Middle Drum (MD). The TA BRM and LR stations cover 3 to 33 degrees in elevation, while the TA MD, together with the TA low energy extension (TALE) FD, cover 3 to 57 degrees. In addition, there is a TALE infill array, which consists of 400 and 600 m spaced counters placed in front of the TA MD site at distances ranging from 1.5 to 3 km.
The TA SD observes cosmic rays above 10^18.2 eV with the most statistics. The TA FD stand alone measurement, on the other hand, is sensitive to cosmic rays above 10^17.2 eV. Because of a 10% duty cycle, it provides the best statistics in 10^17.2 eV to 10^18.5 eV range. Together with the TALE, the TA FD observes cosmic rays down to 10^15.6 eV. We report the energy spectrum of cosmic rays obtained by a combination of TA SD, TA FD and TALE measurements.
Primary author
Dr
Toshihiro FUJII
(KICP University of Chicago, ICRR University of Tokyo)