| Autor: |
Kou Zhao, Qiang Zeng, Yaju Li, Shu Hang Gong, Yifan Wu, Xiangyu Shi, Jinrui Ye, Xueqi Liu, Xinwei Wang, Dongbin Qian, Liangwen Chen, Shaofeng Zhang, Lei Yang, Xinwen Ma |
| Předmět: |
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| Zdroj: |
JAAS (Journal of Analytical Atomic Spectrometry); Oct2024, Vol. 39 Issue 10, p2374-2381, 8p |
| Abstrakt: |
An experimental study on the packing thickness (PT) dependent plasma emission caused by laser ablating thin-layer microgranular samples in air was conducted using three sets of size-selected copper grains (median size d50 = 53 mm, 72 mm, and 100 mm, respectively). For each size-selected case, the PT parameter was tuned from 0.15 to 1.00 mm through varying the amount of grains packed into a vessel with a steel bottom wall and the emission spectra of laser-induced plasma were measured at various PT. It is found that there is a striking threshold phenomenon in the measured behavior of PTdependent plasma emission. Specifically, when PT is less than a threshold PTth, the emission intensity exhibits an exponential decreasing with incremental thickness; however, when it exceeds PTth, the emission intensity becomes almost constant. It is also found that the PTth slightly depends on grain size but the ratio of PTth to d50 seems to be size independent. Combining the mechanical fundamentals of granular materials, we interpreted the findings by considering a PT-dependent effect of the vessel's bottom on the formation circumstance of a laser-induced plasma. This work has practical significance in assessing a threshold thickness above which laser-induced breakdown spectroscopy, as an analytical technique to quantify elements embedded in microgranular materials, is viable regardless of PT difference. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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