Background Stability and Annual Modulation Test Using PICOLON Ultra-Pure NaI(Tl) Detector
Abstract The dark matter observation claimed by the DAMA/LIBRA experiment has been a long-standing puzzle within the particle physics community. NaI(Tl) crystals with radiopurity comparable to DAMA/LIBRA’s are essential for adequate verification. Existing experiments using a NaI(Tl) target have been hampered by the high radioactivity concentration of NaI(Tl) crystals. The Pure Inorganic Crystal Observatory for LOw-energy Neutr(al)ino (PICOLON) experiment conducts an independent search for Weakly Interacting Massive Particles using the highest-purity NaI(Tl) crystals. In 2020, a PICOLON NaI(Tl) crystal (Ingot#85) reached the same purity level as DAMA/LIBRA crystals. The DAMA/LIBRA group has stressed that verifying their signal requires high-purity NaI(Tl) crystals with long-term stability. Based on a six-month measurement, we have confirmed the long-term stability of its radiopurity. This stability provides a significant advantage for future efforts to adequately verify the DAMA/LIBRA result using NaI(Tl) crystals. In this paper, we present the background stability of purity in the Ingot#94 NaI(Tl) detector, which was produced using the Ingot#85 purification method, along with the first annual modulation search conducted by the PICOLON experiment.
Authors
- K. Yasuda
- K. Imagawa
- S. Umehara (ORCID: https://orcid.org/0000-0003-2176-079X)
- S. Yoshida (ORCID: https://orcid.org/0000-0003-2480-5105)
- R. Hazama
- K. Nakamura (ORCID: https://orcid.org/0000-0003-3302-7325)
- T. Iida (ORCID: https://orcid.org/0000-0002-4052-5392)
- T. Shima (ORCID: https://orcid.org/0009-0006-5403-550X)
- Kumiko Kotera (ORCID: https://orcid.org/0000-0002-6337-0696)
- K. Fushimi (ORCID: https://orcid.org/0000-0001-5107-6724)
- K. Hata (ORCID: https://orcid.org/0000-0002-3458-1144)
- A. Kozlov (ORCID: https://orcid.org/0000-0002-6679-3985)
- Yoshio Takemoto (ORCID: https://orcid.org/0000-0001-5042-2891)
- H. Ikeda (ORCID: https://orcid.org/0000-0001-7008-4412)
- H. Ito (ORCID: https://orcid.org/0000-0002-8446-3349)
- R. Orito
- M. Koga
- T. Kishimoto
- H. Ejiri
- K. Inoue
- Yuto Urano (ORCID: https://orcid.org/0009-0004-3646-2781)
Institutions
- Osaka Sangyo University (JP)
- University of Tsukuba (JP)
- Nakanihon Automotive College (JP)
- Unitika (Japan) (JP)
- Tohoku University (JP)
- Osaka Butsuryo University (JP)
- Toneyama National Hospital (JP)
- Kavli Institute for the Physics and Mathematics of the Universe (JP)
- Kobe University (JP)
- National Research Nuclear University MEPhI (RU)
- Tokushima University (JP)
- The University of Osaka (JP)
Publication Details
- Journal
- Progress of Theoretical and Experimental Physics
- Published
- 2025-11-12
- DOI
- https://doi.org/10.1093/ptep/ptaf160
- Primary Topic
- Dark Matter and Cosmic Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00