Computational study on ion dynamics of MEMS quadrupole mass filter

Abstract

The paper presents the simulation studies for the design of a miniaturized Quadrupole Mass Filter (QMF) based on silicon micromachining technology. Mass spectrometers operating in the range of 1 to 100 amu with the resolution of 1 amu are very useful for science payloads in space missions. The mass filtering action of ions in a filter of length 30 mm with electrodes of radius 250 μm is simulated by standard tools. The complete transmission of ions is examined for various Mathieu parameters which are used to define the operating potentials at the electrodes. The performance parameters namely resolution, mass range and the required design considerations such as initial ion velocity, DC and RF voltages and RF frequency are obtained through the model and the computational program using Mathematica. For the efficient ion transmission, an electrostatic slit with aperture of radius 70 μm is placed before the MEMS QMF. Further, the effects of quadrupole length, focusing voltage and the aperture size on the transmission probability of ions are analyzed.