Dark matter serach with high purity detector

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01104
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Tohoku University
• Principal Investigator: Haruo Ikeda 東北大学, ニュートリノ科学研究センター, 助教 (90400233)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 宇宙暗黒物質 / 極低放射能環境 / 地下実験

Outline of Final Research Achievements

Dark matter has been suggested to exist in the universe but is currently undetected, and its observation requires using detectors with minimal radioactive impurities in an environment with extremely low environmental radiation. In this study, we developed a new hybrid detector that combines ultra-pure NaI(Tl) crystals to detect reactions with dark matter and scintillating films to distinguish environmental radiation and detector structures. For this purpose, a new method was developed to observe the radiative contamination in the scintillating film with high sensitivity. Two types of hybrid detectors with different scintillating film thicknesses were fabricated, and their performance was observed in the lead shield at the Kamioka Underground Experimental Facility to evaluate their performance.

Free Research Field

素粒子実験

Academic Significance and Societal Importance of the Research Achievements

宇宙暗黒物質観測のための高純度NaI(Tl)結晶とシンチレーションフィルムを組み合わせたハイブリッド検出器の新規開発の結果、炭化水素フィルムに含まれる放射性不純物量のICP-MSを用いて高感度で測定する技術開発に成功した。検出器の性能評価をするのにノイズの影響が大きくその除去が重要であり、検出器を構成する部材の不純物含有量に加えて考慮すべき点があることが判明した。宇宙暗黒物質観測に欠かせない検出器の長期安定性の確認がなされた。