Ionic species in laser-produced plasma plume are generally analyzed by the time-of-flight method using a charge collector placed near to the target surface. One of the shortcomings of these methods is sacrifice of the important information for large mass cluster ions and the different charge states of atomic ions. In the present manuscript, design, development, and optimization procedure of a modified Wiley–McLaren type time-of-flight mass spectrometer (TOFMS) for the diagnostics of ions and cluster distribution in laser produced plasma (LPP) plume is presented. Second harmonic (532nm) from a pulsed Nd:YAG laser is used to ablate aluminium disk in a vacuum chamber evacuated to base pressure of 7 10⁻⁸ mbar. The mass spectrometric results of aluminium (Al) plasma are presented and discussed in detail. To minimize the degradation in detection and mass resolution of spectrometer due to the wide angular and energy spared of the ions in the plasma plume, optimization of the TOF spectrometer in different configurations, single as well as a double field, is also discussed. Cluster ions as large as and multiply charged ions (MCI) up to Al¹¹⁺ are observed in the mass spectra. The possible pathways for the production of MCI and cluster ions are discussed on the basis of the Coulomb explosion mechanism. The dependence of ion distribution on the laser fluence is also discussed.

激光产生的等离子体羽流中的离子种类通常通过飞行时间方法使用放置在目标表面附近的电荷收集器进行分析。这些方法的缺点之一是牺牲了大质量团簇离子和原子离子不同电荷状态的重要信息。在本手稿中，介绍了改进的 Wiley-McLaren 型飞行时间质谱仪 (TOFMS) 的设计、开发和优化程序，用于诊断激光产生的等离子体 (LPP) 羽流中的离子和簇分布。来自脉冲 Nd:YAG 激光的二次谐波 (532nm) 用于在真空室中烧蚀铝盘，真空室被抽真空至基本压力为 7 10 ^-8毫巴。详细介绍并讨论了铝 (Al) 等离子体的质谱结果。为了最大限度地减少由于等离子体羽流中离子的宽角度和能量节省而导致的光谱仪检测和质量分辨率的下降，还讨论了在不同配置、单场和双场中优化 TOF 光谱仪。在质谱中可以观察到与 Al ¹¹⁺一样大的团簇离子和多电荷离子 (MCI) 。在库仑爆炸机制的基础上讨论了产生 MCI 和团簇离子的可能途径。还讨论了离子分布对激光能量密度的依赖性。