Development of a continuous stable isotopic measuring system for precise separate estimation of sources and sinks of greenhouse gases

利用红外光谱分析技术，研制了二氧化碳稳定同位素组成的精密连续测量系统。选择了适合精密同位素测量的各同位素的中红外吸收谱线。研制了一种原型测量系统，该系统配备了分布反馈量子级联激光器，发射的光的波长带包括选定的吸收线。利用该系统，可以测量二氧化碳的吸收光谱，从而可以识别选定的吸收线。虽然通过这项研究已经形成了同位素测量系统的基本结构，但仍有必要进一步改进，以便在观测点进行精确的连续测量。

Development of a precise continuous measuring system of stable isotopic ratios of carbon dioxide has been made using an infrared spectroscopic technique. Mid-infrared absorption lines of each isotopologue suitable for precise isotopic measurement have been selected. A proto-type measuring system has been produced, which is equipped with a distributed feedback quantum cascade laser emitting the light with the wave length band including the selected absorption lines. Using this system, absorption spectrum of carbon dioxide can be measured, so that the selected absorption lines can be identified. Although the fundamental structure of the isotopic measuring system has been developed through this study, it has been suggested that further improvement is necessary for precise continuous measurement at observation sites.