Investigation of Diamond-Forming Flames Using Advanced Laser Diagnostics and Laser Enhancement of the Deposition Rate

摘要-Lucht和Glumac这是一项对低压钻石形成火焰中的化学和传输过程进行的详细的实验和理论研究。重点研究了沉积衬底附近的温度分布和自由基物种的浓度分布。在一定的火焰压力、化学计量和总质量流量范围内，对温度和自由基物种H(原子氢)、OH(羟基)、C(原子碳)和CH(甲基)进行了广泛的测量，并与数值火焰模型进行了比较。实验工作在Robert Lucht博士的实验室中进行，该实验室拥有必要的低压火焰仪器和激光诊断设备；建模工作在Nick Glumac博士的实验室中完成。温度测量使用氢相干反斯托克斯拉曼光谱(H2 CARS)。诊断性研究的重点是解决近底物区域的梯度。使用了在其他火焰合成环境中已成功应用的火焰模型。模型以火焰温度分布和过程参数作为输入，预测了组分分布；通过灵敏度分析考察了实验和计算的差异，探讨了动力学和输运速度的影响。

Abstract - Lucht and Glumac This is a detailed investigation, both experimental and theoretical, of the chemistry and transport processes in low-pressure diamond-forming flames. The focus is on profiles of temperature and concentrations of radical species near the deposition substrate. Extensive measurements of temperature and of the radical species H (atomic hydrogen), OH (hydroxyl), C (atomic carbon), and CH (methyne) are performed for a range of flame pressures, stoichiometries, and total mass flow rates and are compared with numerical flame models. The experimental work is performed in Dr. Robert Lucht's laboratory which has the necessary low-pressure flame apparatus and laser diagnostic equipment; the modeling is done in Dr. Nick Glumac's laboratory. Temperature measurements are made using hydrogen coherent anti-Stokes Raman spectroscopy (H2 CARS). The emphasis in the diagnostic studies is in resolving the gradients in the near-substrate region. A flame model that has been applied successfully in other flame synthesis environments is used. The flame temperature profile and process parameters are used as input, and the model predicts the species profiles; differences between experiment and computation are investigated with a sensitivity analysis to explore the influences of kinetic and transport rates.