Increasing the Signal-to-Noise Ratio of a Mass Spectrometer Using a Velocity Filter

Strofio is a mass spectrometer, aboard the BepiColombo mission, that utilizes a time-of-flight method to determine the mass-per-charge of each particle entering its aperture in order to study the chemical composition of the exosphere of Mercury. Optimization of Strofio involves finding a balance between system efficiency and mass resolution while increasing the signal-to-noise ratio. In order to ensure our data is exospheric in nature, we must separate the Mercury environment from the background environment. The background environment is made up of thermal particles produced from sources like the outgassing of the spacecraft as well as from the instrument itself. This problem can be addressed by assigning the correct voltages to the source apparatus, thereby realizing a background filter. This filter works best in Mach 2 or larger regimes to ensure the targeted particles do not get filtered out with the background. My work focuses on writing and running a series of computer simulations that optimize the velocity filter in accordance with the configuration of the flight model.