The performance of miniaturized ion trap mass analyzers is limited, in part, by the accuracy with which electrodes can be fabricated and positioned relative to each other. Alignment of plates in a two-plate planar LIT is ideal to characterize misalignment effects, as it represents the simplest possible case, having only six degrees of freedom (DOF) (three translational and three rotational). High-precision motorized actuators were used to vary the alignment between the two ion trap plates in five DOFs—x, y, z, pitch, and yaw. A comparison between the experiment and previous simulations shows reasonable agreement. Pitch, or the degree to which the plates are parallel along the axial direction, has the largest and sharpest impact to resolving power, with resolving power dropping noticeably with pitch misalignment of a fraction of a degree. Lateral displacement (x) and yaw (rotation of one plate, but plates remain parallel) both have a strong impact on ion ejection efficiency, but little effect on resolving power. The effects of plate spacing (y-displacement) on both resolving power and ion ejection efficiency are attributable to higher-order terms in the trapping field. Varying the DC (axial) trapping potential can elucidate the effects where more misalignments in more than one DOF affect performance. Implications of these results for miniaturized ion traps are discussed.

Open image in new window

小型化离子阱质量分析仪的性能部分受限于电极的制造精度和相对位置。两板式平面LIT中板的对齐是表征失准效果的理想选择，因为它代表了最简单的情况，只有六个自由度（DOF）（三个平移和三个旋转）。高精度电动执行器用于在五个自由度（x，y，z，俯仰和偏航）中改变两个离子阱板之间的对齐方式。实验与先前模拟之间的比较显示出合理的一致性。间距，即平板沿轴向平行的程度，对分辨力具有最大和最尖锐的影响，而分辨力随间距错位的几分之一而显着下降。横向位移（x）和偏航角（一块板旋转，但板保持平行）都对离子喷射效率有很大影响，但对分辨能力影响很小。板间距（y位移）对分辨能力和离子喷射效率的影响可归因于俘获场中的高阶项。改变直流（轴向）俘获电势可以阐明一个以上自由度中更多的未对准影响性能的影响。讨论了这些结果对小型离子阱的影响。板间距（y位移）对分辨能力和离子喷射效率的影响可归因于俘获场中的高阶项。改变直流（轴向）俘获电势可以阐明一个以上自由度中更多的未对准影响性能的影响。讨论了这些结果对小型离子阱的影响。板间距（y位移）对分辨能力和离子喷射效率的影响可归因于俘获场中的高阶项。改变直流（轴向）俘获电势可以阐明一个以上自由度中更多的未对准影响性能的影响。讨论了这些结果对小型离子阱的影响。

在新窗口中打开图像