7th International Symposium on Ultra High Energy Cosmic Rays (UHECR) 2024

Calibration of the TA Fluorescence Detectors and Systematic Uncertainties in UHECR Analysis

Not scheduled

20m

Canelo Room ( Thesaurus Convention and Exhibition Centre)

Poster

Speaker

Takayuki Tomida (Academic Assembly School of Science and Technology Institute of Engineering, Shinshu University, Nagano, Nagano, Japan)

Description

Accurate calibration of the Telescope Array Fluorescence Detector (TA-FD) and the atmosphere is crucial for precise analysis of Ultra High Energy Cosmic Rays (UHECRs) using the atmospheric fluorescence method. This presentation focuses on two key aspects of calibration: the pointing direction of the TA-FD and the atmospheric transparency as measured by the Vertical Aerosol Optical Depth (VAOD). The pointing direction of the TA-FD was analyzed with an accuracy of ±0.03 degrees using the Opt-copter, a drone-board LED light source. We estimate the impact of this pointing accuracy on cosmic ray analysis, including the biases and systematic uncertainties it introduces.
Additionally, the TA experiment continuously observes UHECRs with the FD, capturing air showers induced by primary UHECRs. Monthly VAOD values, determined through CLF operation, exhibit a seasonal dependence. We will discuss how incorporating this seasonal variation into air shower analysis can improve the accuracy of primary energy
and Xmax measurements, along with the associated systematic uncertainties.

Presentation materials

poster_uhecr2024_calibration_v3.pdf