# ICRC 2021

Jul 12 – 23, 2021
Online
Europe/Berlin timezone

## Cosmic ray energy spectrum in the 2nd knee region measured by the TALE-SD array

Jul 14, 2021, 12:00 PM
1h 30m
03

#### 03

Talk CRI | Cosmic Ray Indirect

### Speaker

Koki Sato (Osaka city university)

### Description

The Telescope Array Low energy Extension (TALE) experiment in Utah, U.S.A., consists of 10 atmospheric fluorescence telescopes and 80 Surface Detectors (SDs) spread over an area of 21 $km^2$. The SD array consists of 40 SDs at 400 m spacing and 40 SDs at 600 m spacing. The TALE-SD was completed in February 2018 and has been in steady operation since then, triggering at a rate of about 30 air shower events in 10 minutes. We have developed the software to measure the energy spectrum of cosmic rays from the data obtained by TALE-SD. The performance of the software was evaluated by using air shower events generated by Monte Carlo simulation. We estimate that when the energy of the primary cosmic ray is $10^{18.0}$eV, the accuracy of energy determination is 15%, the accuracy of arrival direction determination is 1.5°, and the aperture is 15 $km^2$ sr. Furthermore, we obtained the energy spectrum of cosmic rays from the actual data obtained by the TALE-SD array from October to the end of November 2019. In this presentation, I will report these results.

Collaboration Telescope Array Experimental Results

### Primary authors

Koki Sato (Osaka city university)

### Presentation materials

There are no materials yet.