Miniature Universal Sampling System for Scientific Instruments Project

Characterize the performance of a low-temperature plasma discharge for use as an ion source, an ablation tool, and a sterilization tool. The ion source investigation consisted of coupling the low-temperature plasma discharge source to a mass spectrometer. The goal of this investigation is to provide insight into the ion yield and degree of fragmentation of the low-temperature plasma source relative to conventional electron-impact ion sources, as well as providing insight into technical requirements relating to gas usage, and vacuum requirements. Answering these questions will also address the larger question: is a plasma discharge ion source feasible for planetary exploration? The ablation study with the low-temperature plasma consisted of prolonged exposures of metal surfaces to the low-temperature plasma discharge and analyzing surface modifications with scanning electron microscopy. The intent of this study is to identify whether a plasma source can be used to ablate material from a surface and provide depth profiling of that surface when used in conjunction with a mass spectrometer. Sterilization of a surface with plasmas can proceed through passivation where contaminants are simply desorbed from the surface or through deactivation where biological contaminants on a surface are altered or destroyed following exposure to the plasma. This sterilization study with the low-temperature plasma probe focused on deactivation and involved exposure of Bacillus subtilis samples to the low-temperature plasma discharge to ascertain its effectiveness in deactivating these spores. More »