Search for the nuclear electro-magnetic moment of neutron rich Indium isotopes using superfluid helium

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K14300
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Institute of Physical and Chemical Research (2019); Okayama University (2017-2018)
• Principal Investigator: IMAMURA Kei 国立研究開発法人理化学研究所, 開拓研究本部, 特別研究員 (70783158)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 超流動ヘリウム / レーザー分光 / 核モーメント

Outline of Final Research Achievements

In nuclear physics, appearance or dis-appearance of magic number of atomic nucleus in the region of far from stability is one of attracting phenomena in past few decades. This research subject has aimed at searching the nuclear electro-magnetic moment of neutron rich In isotopes whose proton number Z equals 49, and whose neutron numbers N are 80, and 82. Indium isotopes are located at around the double magic number nucleus of Sn (Z=50, N=82). In order to deduce nuclear electro-magnetic moment of such isotopes, we are developing a laser spectroscopy technique utilizing superfluid helium as an effective stopper for highly energetic ion beam. In this research subject, we performed R&D studies as listed below: (i)Construction of pulsed laser source, (iii)Development of the measurement method using laser-microwave double resonance method, and (iii)Evaluating the stopping efficiency of ion beam in superfluid helium using beam energy of 350 MeV per nucleon.

Free Research Field

数物系科学

Academic Significance and Societal Importance of the Research Achievements

当該研究は原子核の安定性にかかわる魔法数について知見を得るために展開された研究である．自然界に存在する安定核種の魔法数は，原子核の殻モデルと知られる理論により説明可能であり，普遍のものであると信じられてきたが，近年の研究により自然界に存在しない不安定核種において消失・出現することが明らかになってきた．このような原子核の安定性に大きくかかわる性質を明らかにすることは，原子核を統一的に理解するうえでも学術的な貢献は大きく，ひいては現代社会が必要とする原子核工学への貢献も期待できる．当該研究の成果は手法適用にこそ至らなかったものの，適用へ向けた各要素開発を大きく進展させることができた．