若手研究者セッション（国際）
第1日 6月10日（月） 14:45～15:00 A会場（中ホール300）
- 1A-O1-1445（2P-11）
YK23-16S調査航海における船上でのマルチターン飛行時間型質量分析計を使った希ガス同位体の測定結果の報告
(1東大・ 2東大先端研・ 3国立科学博物館)
o沼田翔伍1・ 角野浩史2・ 谷健一郎3
The helium isotope ratio (3He/4He) differs among geochemical reservoirs in Earth’s interior, such as the crust, atmosphere, and mantle. Helium in volcanic gases is a mixture derived from these three components. When volcanic activity increases, the contribution of mantle-derived components increases, and the 3He/4He ratio of volcanic gases becomes higher. Regarding the monitoring of volcanic activity, improving temporal resolution is a challenge for using noble gas analysis of volcanic gases.
The purpose of this study is to simplify and enhance the efficiency of the measurement process of 3He/4He ratios of volcanic gases using a portable mass spectrometer (multi-turn time-of-flight mass spectrometer), to establish an on-site measurement, and to implement it practically as a volcano monitoring technique.
We report the results of measurements on board the ship during the YK23-16S cruise of YOKOSUKA, JAMSTEC, alongside those obtained using a magnetic field mass spectrometer in the laboratory for comparison. The samples were seafloor hydrothermal fluid and seawater collected by the Shinkai 6500. The simplified line resulted in a longer purification time for larger gas volume samples, and the counting rate of helium ions was lower than expected.