Isotopic analysis based on terahertz spectrum

• 作者: OA Qijun Chen Yun Liu .Research Center for Planetary Science College of Earth Sciences Chengdu University of Technology .State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences
• 来源期刊: 地球化学学报(英文）
• 学科: 地球科学
• 年，卷（期）: 2025,（5）
• 页码范围: 57-67
• 页数: 11页
• 语种: 中文

摘要

As a new promising detection technology in the terahertz research field, the terahertz time-domain spectroscopy（THz-TDS） has very broad application potential in many fields because its advantage on the characteristic spectrum, wide spectrum and non-destructive analysis of interested substances. In this paper, the terahertz absorption spectra of gases mixed with12CO and 13CO in the spectrum range of 0.5–2.5 THz are measured by terahertz time-domain spectroscopy for the first time. Several isotopologues can be clearly distinguished based on the difference in their rotational energies and the consequent terahertz spectrum. The experimental results show that12CO and13CO have obvious characteristic absorption peaks in the spectrum range of 0.5–2.5 THz due to the difference in rotational energy, and the rotational constant B can be calculated according to the experimental values to distinguish the two gaseous isotopologues. The frequency positions of the characteristic absorption peak measured by this experiment and the rotation constant B calculated according to the experimental values are compared with those previous theoretical calculations and experimental results,and they are in good agreement. This result lays a foundation for developing more sophisticated terahertz instruments to the detection of different isotopologues.