Basic R&D of the veto counter with high B/C using new fluorescent materials for the future K0 rare decay experiment

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K03881
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Yamagata University
• Principal Investigator: Yoshida Hiroshi 山形大学, 学士課程基盤教育機構, 教授 (80241727)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 粒子線検出器 / カロリメーター / シンチレーター

Outline of Final Research Achievements

A basic R&D on scintillators and optical devices of the gamma-ray veto detectors was made for the realization of the next project of the K0 rare decay experiment. We searched for fluorescent materials suitable for sandwich calorimeters, including commercially available recycled materials such as PEN resin and PET resin. Especially, since the response speed of the material was important, the detailed fluorescence lifetime was measured by the time-correlated single-photon counting method using the synchrotron radiation at UVSOR. Several newly developed wave length shifter materials for the optical fiber readout were found to have short fluorescence lifetime of less than 1.5 ns. Favorable results were obtained for the realization of large and long sandwich calorimeters with fast responses that can operate under higher counting rate.

Free Research Field

素粒子原子核物理学

Academic Significance and Societal Importance of the Research Achievements

環境性や経済性や持続性に著しく劣る学問は社会的に許容されないという時代を迎えつつある中で、リサイクル材料を積極的に活用することを目指し、製造に伴う環境負荷の低減を図るとともに、経済性の向上も図ることも本研究の目的にしている。
まだ未解明の点は多いが、電子ビームに対して得られたPET樹脂の時間応答が格段に速く、発光量がプラスティックシンチレーターの1/5程度であるとはいえ、リサイクル材料である（ホームセンター等で市販されている程度の）PET樹脂を検出器として利用する可能性を見出せた意義は大きい。