Simulation of a Miniature Linear Ion Trap with Half-Round Rod Electrodes.

Area of Science:

• Analytical Chemistry
• Instrument Development

Background:

• Miniaturization of ion trap mass analyzers is crucial for developing portable mass spectrometers.
• Conventional HreLIT (Hemispherical Radiofrequency Ion Trap) designs serve as a basis for miniaturization.

Purpose of the Study:

• To propose and theoretically investigate two models of miniaturized HreLIT (2-slit and 4-slit) with a field radius of approximately 2 mm.
• To analyze the relationship between mass resolution, electrode geometry (r/r and stretch distance), and electric fields within the traps.

Main Methods:

• Theoretical simulations were employed to model and analyze the performance of the miniaturized HreLIT designs.
• Investigated the impact of electrode 'stretch' distance and the ratio of field radius to electrode radius (r/r) on mass resolution.

Main Results:

• Both 2-slit and 4-slit models showed comparable maximum resolution at r/r = 2/1.4.
• The 2-slit model achieved approximately 8% higher peak resolution than the 4-slit model, reaching a maximum of 517 with a 1.1 mm stretch.
• Resolution exceeding 1000 for m/z = 119 was theoretically predicted at scan rates of 800 Th/s.

Conclusions:

• The theoretical study confirms the mass spectrometry capability of miniature HreLIT devices.
• The findings provide a foundation for fabricating miniaturized ion trap mass analyzers using MEMS technology.