Investigation of the intrinsic detector background for SMILE-3 balloon experiment
MeV gamma-ray observations are a probe for uncovering various physical phenomena, such as the search for dark matter and primordial black holes, and the study of the nucleosynthesis in the Universe. To achieve high sensitivity in this band, we are developing an electron-tracking Compton camera (ETCC), which combines a gaseous time projection chamber (TPC) and pixelated GSO(Ce) scintillator arrays (PSAs). The ETCC tracks recoil electrons in the TPC and reconstructs Compton events to uniquely determine gamma-ray arrival directions. We are now planning the Sub-MeV/MeV gamma-ray Imaging Loaded-on-balloon Experiment 3 (SMILE-3), which will use an upgraded ETCC from the previous balloon experiment, SMILE-2+, with improved dynamic range and effective area. The first one-day flight of SMILE-3 is scheduled for spring 2027 in Australia. The ETCC has background events originating from radioactive isotopes contained in the GSO(Ce) scintillators. Therefore, we measured the intrinsic background of all GSO(Ce) scintillators to be used in SMILE-3 and investigated their properties to evaluate the feasibility of selecting low-background scintillators.
Authors
- K. Miuchi (ORCID: https://orcid.org/0000-0002-1546-7370)
- M. Mori (ORCID: https://orcid.org/0000-0003-2921-1592)
- Yoshitaka Mizumura (ORCID: https://orcid.org/0000-0001-9213-0678)
- Tomonori Ikeda (ORCID: https://orcid.org/0000-0002-9612-9612)
- Atsushi Takada (ORCID: https://orcid.org/0000-0002-2515-5573)
- Shunsuke Kurosawa (ORCID: https://orcid.org/0000-0001-7873-4969)
- Kenji Hamaguchi (ORCID: https://orcid.org/0000-0001-7515-2779)
- Takatoshi Sato
- Mitsuru Abe (ORCID: https://orcid.org/0000-0001-6974-3580)
- Takeshi Nakamori (ORCID: https://orcid.org/0000-0002-7308-2356)
- Hirotake Tsukamoto (ORCID: https://orcid.org/0000-0003-3214-1652)
- Tomohiko Oka (ORCID: https://orcid.org/0000-0002-9924-9978)
- T. Tanimori (ORCID: https://orcid.org/0000-0003-4427-0961)
- Y. Munakata
- Tatsuya Sawano (ORCID: https://orcid.org/0000-0003-4462-0298)
- J. Kushida (ORCID: https://orcid.org/0000-0002-8002-8585)
- Haruki Iiyama
- S. Deguchi (ORCID: https://orcid.org/0009-0009-1380-0254)
- Ryo Yoshioka
- Masafumi Sakata
- K. Okamoto
- Dai Yaegashi
Publication Details
- Published
- 2025-09-23
- DOI
- https://doi.org/10.22323/1.501.0690
- Primary Topic
- Astrophysics and Cosmic Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- University of Tokyo
- Japan Society for the Promotion of Science
- Japan Aerospace Exploration Agency
- Institute for Cosmic Ray Research, University of Tokyo