Fraunhofer Institute for Physical Measurement Techniques IPM, 79110 Freiburg, Germany.
Sensors (Basel). 2023 Jan 17;23(3):1082. doi: 10.3390/s23031082.
In this study, a new method for the inline measurement of depth profiles on a continuously moving sample with laser-induced breakdown spectroscopy is presented. The ablation profile is generated by ablating the sample with a burst of laser pulses, where the emission spectrum of each laser-induced plasma is analyzed on a spectrometer. A Q-switched Nd:YAG laser at 1064 nm with 10 mJ pulse energy, 6 ns pulse duration and 100 Hz repetition rate was used. The focusing lens for the pulsed laser and a deflection mirror are mounted on a moving stage, which is precisely aligned in height and orientation to the movement of a conveyor belt transporting the sample. The stage speed is actively synchronized to the speed of the moving sample by a wheel encoder to assure that all laser pulses hit the same position at the sample. The feasibility for depth-resolved elemental analysis on moving samples is shown for coatings of electrode foils for lithium-ion batteries. The coating homogeneity was measured at a speed up to 17 m/min. For a 100 μm coating, 10 laser pulses were needed to measure a full depth profile.
本研究提出了一种新的方法，可在连续移动的样品上进行激光诱导击穿光谱的在线深度剖面测量。通过用一系列激光脉冲烧蚀样品来生成烧蚀剖面，其中每个激光诱导等离子体的发射光谱在光谱仪上进行分析。使用了 1064nm 的 Q 开关 Nd：YAG 激光器，脉冲能量为 10mJ，脉冲持续时间为 6ns，重复频率为 100Hz。脉冲激光的聚焦透镜和一个偏转镜安装在一个移动台上，该移动台的高度和方向与输送样品的输送带的运动精确对齐。通过轮式编码器将台速与移动样品的速度主动同步，以确保所有激光脉冲都击中样品的同一位置。对于锂离子电池电极箔的涂层，展示了对移动样品进行深度分辨元素分析的可行性。在高达 17m/min 的速度下测量了涂层的均匀性。对于 100μm 的涂层，需要 10 个激光脉冲来测量完整的深度剖面。
