Charge Detection Mass Spectrometry of Micron-Sized Particles Using a Differential Amplifier

Abstract

We present a novel detector for measuring the charge and mass of micron-sized particles. Detection of charge is based on charge induction on electrodes connected to a custom differential amplifier. Mass is calculated from particle acceleration in an electric field. A custom software program processes the amplifier signals and produces charge and mass calculations, along with calculation uncertainties based on the experimental errors. Using our detector and software, we evaluated charge and mass for clumps of 5 μm silicon dioxide particles. Our detector can potentially be used in interplanetary research missions studying particle size and charge distributions.