Alquaity Awad B S, Es-sebbar Et-touhami, Farooq Aamir
Opt Express. 2015 Mar 23;23(6):7217-26. doi: 10.1364/OE.23.007217.
Pulsed cavity ringdown spectroscopy (CRDS) is used to develop a novel, ultra-fast, high-sensitivity diagnostic for measuring species concentrations in shock tube experiments. The diagnostic is demonstrated by monitoring trace concentrations of ethylene in the mid-IR region near 949.47 cm⁻¹. Each ringdown measurement is completed in less than 1 µs and the time period between successive pulses is 10 µs. The high sensitivity diagnostic has a noise-equivalent detection limit of 1.08 x 10⁻⁵ cm⁻¹ which enables detection of 15 ppm ethylene at fuel pyrolysis conditions (1845 K and 2 bar) and 294 ppb ethylene under ambient conditions (297 K and 1 bar). To our knowledge, this is the first successful application of the cavity ringdown method to the measurement of species time-histories in a shock tube.
脉冲腔衰荡光谱法（CRDS）用于开发一种新型、超快速、高灵敏度的诊断方法，以测量激波管实验中的物种浓度。通过监测949.47 cm⁻¹附近中红外区域乙烯的痕量浓度来演示该诊断方法。每次衰荡测量在不到1微秒内完成，连续脉冲之间的时间间隔为10微秒。这种高灵敏度诊断方法的噪声等效检测限为1.08×10⁻⁵ cm⁻¹，能够在燃料热解条件（1845 K和2巴）下检测到15 ppm的乙烯，在环境条件（297 K和1巴）下检测到294 ppb的乙烯。据我们所知，这是腔衰荡方法首次成功应用于激波管中物种时间历程的测量。
