30TH INTERNATIONAL COSMIC RAY CONFERENCE Physics of the TALE Experiment

The Telescope Array Low Energy Extension (TALE) is a series of detectors to be added to the Telescope Array (TA) experiment to extend its energy coverage to lower energies and increase its aperture at high energies. The combination of TA and TALE will be able to measure the spectrum of ultrahigh energy cosmic rays from 10 to 10 eV, and study all three features of the spectrum: the second knee, the ankle, and the GZK cutoff. At each energy in this range, TA/TALE will be able to measure, in a model independent way, the average depth of shower maximum and hence the composition of cosmic rays. TA/TALE will have excellent pointing resolution for anisotropy studies. The TALE detectors will consist of two fluorescence detectors located 6 km from two TA fluorescence detectors (6 km spacing produces a flat stereo aperture in the region of the ankle), a third fluorescence detector with larger mirrors observing at higher elevation angles (which will observe cosmic rays at lower energies), and an infill array.