Refinement of the High-Energy Gamma-ray Selection for CALET on the International Space Station
Creators: name: Cannady, Nicholas
name: Adriani, Oscar
name: Akaike, Yosui
name: Asano, Katsuaki
name: Aaoka, Yoichi
name: Berti, Eugenio
name: Bigongiari, Gabriele
name: Binns, Walter Robert
name: Bongi, Massimo
name: Brogi, Paolo
name: Bruno, Alessandro
name: Cannady, Nicholas Wade
name: Castellini, Guide
name: Checchia, Caterina
name: Cherry, Walter Robert
name: Collazuol, Gianmaria
name: De Nolfo, Georgia A.
name: Ebisawa, Ken
name: Ficklin, Anthony W.
name: Fuke, Hideyuki
name: Gonzi, Sandro
name: Guzik, T. Gregory
name: Hams, Thomas
name: Hibino, Kinya
name: Ichimura, Masakatsu
name: Ioka, Kunihito
name: Ishizaki, Wataru
name: Israel, Martin H.
name: Kasahara, Katsumasa
name: Kataoka, Jun
name: Kataoka, Ryuho
name: Katayose, Yusaku
name: Kato, Chihiro
name: Kawanaka, Norita
name: Kawakubo, Yuta
name: Kobayashi, Kenko
name: Kohri, Kazunori
name: Krawczynski, Henric S.
name: Krizmanic, John F.
name: Maestro, Paolo
name: Marrocchesi, Pier Simone
name: Messineo, Alberto Maria
name: Mitchell, Jason W.
name: Miyake, Shoko
name: Moiseev, Alexander
name: Mori, Masaki
name: Mori, Nicola
name: Motz, Holger Martin
name: Munakata, Kazuoki
name: Nakahira, Satoshi
name: Nishimura, Jun
name: Okuno, Shoji
name: Ormes, Jonathan
name: Ozawa, Shunsuke
name: Pacini, Lorenzo
name: Pacini, Paolo
name: Rauch, Brian Flint
name: Ricciarini, Ricciarini
name: Sakai, Kazuhiro
name: Sakamoto, Takanori
name: Sasaki, Makoto
name: Shimizu, Yuki
name: Shiomi, Atsushi
name: Spillantini, Piero
name: Stolzi, Francesco
name: Sugita, Satoshi
name: Sulaj, Arta
name: Takita, Masato
name: Tamura, Tadahisa
name: Terasawa, Toshio
name: Torii, Shoji
name: Tsunesada, Yoshiki
name: Uchihori, Yukio
name: Vannuccini, Elena
name: Wefel, John P.
name: Yamaoka, Kazutaka
name: Yanagita, Shohei
name: Yoshida, Atsumasa
name: Yoshida, Kenji
name: Zober, Wolfgang V.
Publisher: name: Proceedings of Science
Year: 2023

description: 38th International Cosmic Ray Conference (ICRC2023), 26 July - 3 August, 2023, Nagoya, Japan
description: The Calorimetric Electron Telescope (CALET) is a deep electromagnetic calorimeter designed for the measurement of cosmic-ray electrons on the International Space Station. Deployed on the Exposed Facility of the Japanese Experiment Module since August 2015, it observes cosmic-ray electrons with energies up to above 10 TeV and hadrons up to PeV total energies. It is also sensitive to gamma rays in the energy range from 1 GeV to 1 TeV. At energies above ~100 GeV, sensitivity is lost in the gamma-ray selection as previously defined. This is due in large part to the contamination of the charge measurement in the CHD (Charge Detector) and the IMC (Imaging Calorimeter) by backscattered particles from the electromagnetic shower in the TASC (Total Absorption Calorimeter). In this work, we implement a revision to the photon selection criteria using a significantly increased simulated dataset, increasing CALET's exposure at these energies significantly. Furthermore, the allowable geometry for incident photons is expanded and the energy reconstruction revised to tighten the energy resolution for highly inclined tracks. We validate the distributions used for the selection through comparison with real data, evaluate the changes to the instrument response functions, and assess the implications for the flight data analysis of gamma rays with CALET.