Systematic study of cold ion-polar molecule reactions for interstellar chemistry

2018 Fiscal Year Final Research Report

• Project/Area Number: 15H03753
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Geochemistry/Cosmochemistry
• Research Institution: Sophia University
• Principal Investigator: Okada Kunihiro 上智大学, 理工学部, 教授 (90311993)
• Co-Investigator(Kenkyū-buntansha): 崎本 一博 国立研究開発法人宇宙航空研究開発機構, その他部局等, 助教 (60170627)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: イオン極性分子反応 / シュタルク分子速度フィルター / イオントラップ / クーロン結晶 / 星間分子 / レーザー冷却

Outline of Final Research Achievements

The purpose of this study is to develop a new temperature variable Stark velocity filter in order to clarify the reaction temperature dependence of various ion-polar molecular reactions at low temperatures. In this study, we developed a Wavy Stark velocity filter and succeeded in changing the translational temperature of acetonitrile (CH3CN) over 6.5-110 K without changing the output beam position of polar molecular beams. Additionally, we succeeded in measuring the translational temperature dependence of the reaction rate constant of CH3CN + Ne+ → products and found that there is a large translational temperature dependence in the reaction probability. The completion of the Wavy Stark velocity filter has paved the way to experimentally reveal the translational temperature dependence of ion-polar molecular reactions at low temperatures.

Free Research Field

原子分子物理学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果によって，これまで実験が困難であった低温（-260℃～-173℃）におけるイオンと極性分子の気相化学反応を測定する手段を新たに提供できるようになったこと，およびそれを用いた実証実験に成功したことが学術的に重要な貢献であると考える。