Investigation of the origin of heavy elements via precise mass measurements of unexplored nuclei by using Rare RI Ring

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K14730
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 15020:Experimental studies related to particle-, nuclear-, cosmic ray and astro-physics
• Research Institution: Institute of Physical and Chemical Research (2020-2021); University of Tsukuba (2019)
• Principal Investigator: Mukai Momo 国立研究開発法人理化学研究所, 仁科加速器科学研究センター, 基礎科学特別研究員 (10823726)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 飛行時間検出器 / 位置検出器 / 質量測定

Outline of Final Research Achievements

We developed a high-resolution time-of-flight (TOF) detector with low material-density for precise mass spectroscopy of unstable nuclei in Rare-RI-Ring (RIKEN/RIBF). The dependency of detection efficiency on the beam atomic number and time resolution of the TOF detector were investigated using high-energy ion beams. Our TOF detector has satisfied with the performances required for the precise mass spectroscopy in Rare-RI-Ring. The physics experimental programs in Rare-RI-Ring with the TOF detector are ongoing. Based on the technique of the present TOF detector, we are also developing a position sensitive detector with low material-density for the further precise mass-measurement in Rare-RI-Ring.

Free Research Field

原子核物理学

Academic Significance and Societal Importance of the Research Achievements

本研究課題により、約20 psの高時間分解能での高エネルギーイオンビームの飛行時間検出が可能となった。開発した検出器はビームの通過物質が薄膜一枚のみであり、従来のプラスチックシンチレータ等による通過ビームのエネルギー損失などの影響を1/100以下に抑えられる。本検出器を利用することで、稀少RIリングでの精密質量測定をはじめ、高エネルギーイオンビームを用いた施設で稀少な原子核の様々な核分光実験を実施でき、重元素合成過程の解明に寄与することができる