A swept-wavelength external cavity quantum cascade laser is used to measure time-resolved ${}^{15}{\mathrm{NH}}_3$ and ${}^{14}{\mathrm{NH}}_3$ concentrations and isotope ratios in a turbulent plume source located at 10 m standoff distance. Measurements show excellent agreement with expected values of isotope ratios for samples with natural and enriched ${}^{15}\mathrm{N}$ abundance. Detection sensitivity of 150 ppb*m is demonstrated for a 50 ms measurement interval, improving to 10 ppb*m with 10 s averaging, with isotopic precision as good as 0.8%.

中文翻译：

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使用扫频外腔量子级联激光实时检测氨气中的氮同位素

扫描波长外腔量子级联激光器用于测量时间分辨 ${}^{15}{\mathrm{NH}}_3$ 和 ${}^{14}{\mathrm{NH}}_3$距离为10 m的湍流烟羽源中的浓度和同位素比。测量结果表明，天然和富集样品的同位素比预期值具有极好的一致性${}^{15}\mathrm{ñ}$丰富。在50 ms的测量间隔内显示出150 ppb * m的检测灵敏度，平均10 s提高到10 ppb * m，同位素精度高达0.8％。