基于中红外差频光源的高精度二氧化碳同位素探测

项目名称： 基于中红外差频光源的高精度二氧化碳同位素探测

项目编号： No.41205021

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 大气科学学科

项目作者： 曹振松

作者单位： 中国科学院合肥物质科学研究院

项目金额： 26万元

中文摘要： 二氧化碳的来源及其输运过程是全球碳循环研究的前沿课题，它可以通过测量大气中二氧化碳稳定同位素丰度确定。目前色谱、质谱、火焰电离等技术均可用于探测同位素丰度，然而难以做到实时在线测量和分析。本项目拟利用二氧化碳分子在中红外波段具有强吸收的特点（带有C=O化学键的分子在中红外波段有很强的基频吸收），把基于差频技术的中红外激光光源和调制技术结合起来，开展实际大气中二氧化碳稳定同位素测量研究。通过系统稳频以及精确控制进样气体压力和温度，提高探测系统稳定性；分析不同二氧化碳浓度下系统的非线性响应以及实际大气中水汽对测量结果的影响，提高测量的准确度；结合主成分分析法和卡尔曼滤波器，提高测量的精确度。为生物学、地质学、大气探测和全球碳循环等领域提供一种有效的测量手段。

中文关键词： 同位素探测；差频光源；主成分分析；Kalman滤波；

英文摘要： Carbon Dioxide(CO2) is one of the primary greenhouse gases in the Earth's atmosphere, its sink and source is the frontier problem in the global carbon cycle, this problem can be figured out using its isotopologue measurements. There are several approaches that could be used to measure isotopologue, such as chromatography, mass spectrometry and flame ionization detector, however, they are not suitable for the in-situ and/or on line measurements. The proposal proposed here is going to take the advantage of the strong CO2 absorption lines in the mid -infrared wavelength region (via difference frequency generation technique), to measure the CO2 isotopologue in the ambient air. Several strategies which are very helpful to improve the system performance will be implemented into the project: 1) use line lock and modulation techniques to stabilize the system, 2)analyze the system performance versus different CO2 and water vapor concentration in the ambient air, and 3)add principal component analysis and kalman filter alogrithms to improve the system accuracy. The project is supposed to supply an efficient measurement alternative to the biology, geology, atmospheric trace gases measurement and global carbon cycle.

英文关键词： Isotope Measurement；Difference Frequency Generation；Principal Component Analysis；Kalman Filter；