Abstract

The axial aberration of the ion-optical system of a static mass analyzer is one of the main factors limiting the transmission and sensitivity of the instrument. We described an algorithm for selecting the optimal collimating system for a mass analyzer, which makes it possible to decrease this aberration effectively, with minimal loss in the intensity of the mass spectral lines. The algorithm is based on the representation of the considered aberration in the phase space as an ellipse and the optimal approximation of this aberration ellipse by a polygon with a given number of vertices. In the absence of constraints, the solution of the corresponding optimization problems is in phase polygons generated by regular polygons inscribed in a unit circle or circumscribed around a unit circle with the same number of vertices. After that, the unit circle along with the polygons is “stretched” to the size of the specified aberration ellipse along its main axes. Additional freedom of the rotation of the original polygon around the center of the unit circle can be used to position auxiliary slits of the collimating system more conveniently.

中文翻译：

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优化静态质量分析仪接受度的几何方面

摘要

静态质量分析仪的离子光学系统的轴向像差是限制仪器透射率和灵敏度的主要因素之一。我们描述了一种为质谱分析仪选择最佳准直系统的算法，该算法可以有效地降低像差，同时使质谱线的强度损失最小。该算法基于表示为椭圆的相空间中的像差表示，以及具有给定顶点数量的多边形对该像差椭圆的最佳逼近。在没有约束的情况下，相应优化问题的解决方案是在由多边形内切出的规则多边形生成的相多边形中，或者在具有相同数量顶点的单元圆周围外接的规则多边形生成相多边形。之后，单位圆和多边形一起沿其主轴“拉伸”到指定像差椭圆的大小。原始多边形围绕单位圆心旋转的附加自由度可用于更方便地定位准直系统的辅助狭缝。