We describe a setup for the analysis of secondary ions and neutrals emitted from solid surfaces and two-dimensional materials during irradiation with highly charged ions. The ultrahigh vacuum setup consists of an electron beam ion source to produce bunches of ions with various charge states q (e.g., Xe¹⁺–Xe⁴⁶⁺) and thus potential energies, a deceleration/acceleration section to tune the kinetic energy of the ions in the range of 5 keV to 20 × q keV, a sample stage for laser-cleaning and positioning of freestanding as well as supported samples, a pulsed excimer laser for post-ionization of sputtered neutrals, and a reflectron type time-of-flight mass spectrometer, enabling us to analyze mass and velocity distributions of the emitted particles. With our setup, contributions from potential and kinetic energy deposition can be studied independently of each other. Charge dependent experiments conducted at a constant kinetic energy show a clear threshold for the emission of secondary ions from SrTiO₃. Data taken with the same projectile charge state, but at a different kinetic energy, reveal a difference in the ratio of emitted particles from MoS₂. In addition, first results are presented, demonstrating how velocity distributions can be measured with the new setup.

中文翻译：

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慢速，高电荷离子辐照过程中粒子发射的飞行时间质谱

我们描述了一种用于分析高电荷离子辐照期间从固体表面和二维材料中释放出的次级离子和中性离子的装置。超高真空设置包括一个电子束离子源，以产生具有各种电荷状态q（例如Xe ¹⁺ -Xe ⁴⁶⁺）和势能的一束离子；还有一个减速/加速部分，用于调节离子的动能在5 keV至20× q的范围内keV，用于独立和支撑样品的激光清洗和​​定位的样品台，用于溅射中性离子后电离的脉冲准分子激光，以及反射式飞行时间质谱仪，使我们能够分析质量和速度发射粒子的分布。通过我们的设置，可以相互独立地研究势能和动能沉积的贡献。在恒定动能下进行的与电荷有关的实验表明，从SrTiO ₃发出次级离子的阈值很明确。在相同的弹丸电荷状态下，但以不同的动能获得的数据表明，从MoS ₂发射的粒子的比例有所不同。此外，还提供了第一个结果，展示了如何使用新设置测量速度分布。