Development of beam-through-type gas-cell for mass measurement of proton-rich nuclei

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K14750
• 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
• Principal Investigator: Kimura Sota 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, 特別研究員 (10827348)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ガスセル / 多重反射型飛行時間式質量分析 / 精密質量測定 / 不安定核

Outline of Final Research Achievements

A beam-through-type gas cell has been developed for the precise mass measurement of proton-rich nuclei. A new apparatus consisting of a beam-through-type gas cell and a multi-reflection time-of-flight mass spectrometer was installed in the superconducting in-flight RI beam separator BigRIPS at RIKEN, and the mass measurement experiment of neutron-rich nuclei was performed as commissioning. As a result, the masses of 88,89As, and 112Mo were experimentally determined for the first time. The beam-through-type gas cell was confirmed to have reached the practical stage, although there still is room for improvement.

Free Research Field

原子核物理（実験）

Academic Significance and Societal Importance of the Research Achievements

不安定原子核を用いた種々の精密測定実験にはエネルギーの揃った高純度の低エネルギーイオンビームが必要とされている。しかし不安定核は高エネルギーのイオンとして生成されるためガスセルを用い一度低速イオンに変換する。本研究で開発したビーム透過型ガスセルは大強度の入射ビームに対してその効率を保ちつつ、更にガスセル内での不純物イオンの発生低減を狙ったものであり、不安定原子核を用いた実験の可能性を大きく広げるものである。