GRBAlpha: the smallest astrophysical space observatory -- Part 1: Detector design, system description and satellite operations

András Pál; Masanori Ohno; László Mészáros; Norbert Werner; Jakub Řípa; Balázs Csák; Marianna Dafčíková; Marcel Frajt; Yasushi Fukazawa; Peter Hanák; Ján Hudec; Nikola Husáriková; Jakub Kapuš; Miroslav Kasal; Martin Kolář; Martin Koleda; Robert Laszlo; Pavol Lipovský; Tsunefumi Mizuno; Filip Münz; Kazuhiro Nakazawa; Maksim Rezenov; Miroslav Šmelko; Hiromitsu Takahashi; Martin Topinka; Tomáš Urbanec; Jean-Paul Breuer; Tamás Bozóki; Gergely Dálya; Teruaki Enoto; Zsolt Frei; Gergely Friss; Gábor Galgóczi; Filip Hroch; Yuto Ichinohe; Kornél Kapás; László L. Kiss; Hiroto Matake; Hirokazu Odaka; Helen Poon; Aleš Povalač; János Takátsy; Kento Torigoe; Nagomi Uchida; Yuusuke Uchida

arXiv · 2302.10048

GRBAlpha: the smallest astrophysical space observatory -- Part 1: Detector design, system description and satellite operations

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Abstract

Aims. Since launched on 2021 March 22, the 1U-sized CubeSat GRBAlpha operates and collects scientific data on high-energy transients, making it the smallest astrophysical space observatory to date. GRBAlpha is an in-obit demonstration of a gamma-ray burst (GRB) detector concept suitably small to fit into a standard 1U volume. As it was demonstrated in a companion paper, GRBAlpha adds significant value to the scientific community with accurate characterization of bright GRBs, including the recent outstanding event of GRB 221009A. Methods. The GRB detector is a 75x75x5 mm CsI(Tl) scintillator wrapped in a reflective foil (ESR) read out by an array of SiPM detectors, multi-pixel photon counters by Hamamatsu, driven by two separate, redundant units. To further protect the scintillator block from sunlight and protect the SiPM detectors from particle radiation, we apply a multi-layer structure of Tedlar wrapping, anodized aluminium casing and a lead-alloy shielding on one edge of the assembly. The setup allows observations of gamma radiation within the energy range of 70-890 keV with an energy resolution of ~30%. Results. Here, we summarize the system design of the GRBAlpha mission, including the electronics and software components of the detector, some aspects of the platform as well as the current way of semi-autonomous operations. In addition, details are given about the raw data products and telemetry in order to encourage the community for expansion of the receiver network for our initiatives with GRBAlpha and related experiments.

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András Pál, Masanori Ohno, László Mészáros, Norbert Werner, Jakub Řípa, Balázs Csák, Marianna Dafčíková, Marcel Frajt, Yasushi Fukazawa, Peter Hanák, Ján Hudec, Nikola Husáriková, Jakub Kapuš, Miroslav Kasal, Martin Kolář, Martin Koleda, Robert Laszlo, Pavol Lipovský, Tsunefumi Mizuno, Filip Münz, Kazuhiro Nakazawa, Maksim Rezenov, Miroslav Šmelko, Hiromitsu Takahashi, Martin Topinka, Tomáš Urbanec, Jean-Paul Breuer, Tamás Bozóki, Gergely Dálya, Teruaki Enoto, Zsolt Frei, Gergely Friss, Gábor Galgóczi, Filip Hroch, Yuto Ichinohe, Kornél Kapás, László L. Kiss, Hiroto Matake, Hirokazu Odaka, Helen Poon, Aleš Povalač, János Takátsy, Kento Torigoe, Nagomi Uchida, Yuusuke Uchida. 2023-02-20. GRBAlpha: the smallest astrophysical space observatory -- Part 1: Detector design, system description and satellite operations. https://arxiv.org/abs/2302.10048

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