Abstract Study on the excitation process of magnesium atom has been conducted in microwave-assisted laser plasma. Experimentally, an Nd:YAG laser (532 nm, 5 mJ) was directed into the magnesium oxide (MgO) sample in various gases of helium, argon, and air at a reduced pressure to induce a luminous plasma. The plasma emission was significantly enhanced when a microwave (2.45 GHz, 400 W) was introduced into the laser plasma. Results revealed that the emission intensity of the ionic magnesium lines that have relatively low excitation energy (around 4 eV) is high only in helium and argon ambient gases. On the contrary, the intensity of ionic magnesium lines having high excitation energy (8–11 eV) is high only for helium gas. The results suggested that a particular excitation process takes place in the microwave-assisted laser plasma induced in helium and argon gases, namely the excitation mechanism proceeds through metastable atoms overwhelmingly produced in the microwave-assisted laser-induced plasma.

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亚稳态原子在微波辅助激光等离子体中镁原子激发过程中的作用

摘要 对微波辅助激光等离子体中镁原子的激发过程进行了研究。在实验中，Nd:YAG 激光器（532 nm，5 mJ）在减压下被引导到各种氦气、氩气和空气中的氧化镁 (MgO) 样品中，以诱导发光等离子体。当微波 (2.45 GHz, 400 W) 引入激光等离子体时，等离子体发射显着增强。结果表明，仅在氦气和氩气环境气体中，具有相对较低激发能（约 4 eV）的离子镁线的发射强度较高。相反，具有高激发能（8-11 eV）的离子镁线的强度仅对于氦气来说是高的。