Abstract This study computationally explores the possibility of focusing charged aerosol nanoparticles using electrostatics, similar to focusing of electrons and ions. A non-dimensional electrostatic focusing parameter χ e , defined as the ratio of electrostatic potential energy to the kinetic energy of an aerosol nanoparticle, significantly determines focusing performance. The focusing device considered here is a 3-electrode electrostatic (“einzel”) lens. The average focal length of the lens is seen to have an inverse power relationship with χ e . For low values of χ e ∼3 in this study, the particles are seen to cross the lens axis once, while at higher χ e multiple axis cross-over points appear. Similar to electron and ion optics, nanoparticle focusing is also limited by spherical aberration and beam divergence due to finite spread of particles in the inlet cross section of the lens and spatial non-uniformity of the focusing electric field. Other factors that influence focusing performance such as the electrostatic lens geometry, and the distribution of velocity and kinetic energy of the particles at the inlet of the lensing region are recognized, but not considered here for simplicity. In vacuum, good focusing performance (i.e.) a narrow beam of nanoparticles with minimum spherical aberration and small divergence angle is theoretically possible if χ e

中文翻译：

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使用单透镜对气溶胶纳米粒子静电聚焦的计算研究

摘要 本研究通过计算探索了使用静电聚焦带电气溶胶纳米粒子的可能性，类似于电子和离子的聚焦。定义为静电势能与气溶胶纳米颗粒动能之比的无量纲静电聚焦参数 χ e 显着决定了聚焦性能。这里考虑的聚焦装置是一个 3 电极静电（“einzel”）透镜。可以看出，镜头的平均焦距与 χ e 具有反幂关系。对于本研究中 χ e ∼3 的低值，可以看到粒子穿过透镜轴一次，而在较高的 χ e 处出现多轴交叉点。类似于电子和离子光学，由于粒子在透镜入口横截面的有限扩散和聚焦电场的空间非均匀性，纳米粒子聚焦也受到球差和光束发散的限制。其他影响聚焦性能的因素，如静电透镜几何形状，以及透镜区域入口处粒子的速度和动能分布，都被认识到，但为了简单起见，这里不考虑。在真空中，良好的聚焦性能（即）具有最小球差和小发散角的窄纳米粒子束在理论上是可能的，如果 χ e 并且识别了透镜区域入口处粒子的速度和动能分布，但为简单起见，此处不考虑。在真空中，良好的聚焦性能（即）具有最小球差和小发散角的窄纳米粒子束在理论上是可能的，如果 χ e 并且识别了透镜区域入口处粒子的速度和动能分布，但为简单起见，此处不考虑。在真空中，良好的聚焦性能（即）具有最小球差和小发散角的窄纳米粒子束在理论上是可能的，如果 χ e