A carbon nanotube based ion source for planetary space mass spectrometry.

Ion sources are used in mass and energy spectrometry to ionize the neutral particles entering the instrument. The most classical technique used in planetary exploration is hot filaments emitting electrons with few tens of eV and impacting the neutral particles. The main limitations of such emitters are power consumption and outgassing due to heating of their local environment.

Krypton isotopes and noble gas abundances in the coma of comet 67P/Churyumov-Gerasimenko.

The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis mass spectrometer Double Focusing Mass Spectrometer on board the European Space Agency's Rosetta spacecraft detected the major isotopes of the noble gases argon, krypton, and xenon in the coma of comet 67P/Churyumov-Gerasimenko. Earlier, it was found that xenon exhibits an isotopic composition distinct from anywhere else in the solar system. However, argon isotopes, within error, were shown to be consistent with solar isotope abundances.

Prebiotic chemicals-amino acid and phosphorus-in the coma of comet 67P/Churyumov-Gerasimenko.

The importance of comets for the origin of life on Earth has been advocated for many decades. Amino acids are key ingredients in chemistry, leading to life as we know it. Many primitive meteorites contain amino acids, and it is generally believed that these are formed by aqueous alterations.

Detection of argon in the coma of comet 67P/Churyumov-Gerasimenko.

Comets have been considered to be representative of icy planetesimals that may have contributed a significant fraction of the volatile inventory of the terrestrial planets. For example, comets must have brought some water to Earth. However, the magnitude of their contribution is still debated.

Multi-scale simulation of electron emission from a triode-type electron source with a carbon-nanotube column array cathode.

We have designed and fabricated a new type of field electron source for a novel onboard mass spectrometer. The new electron source, which is a field effect emitter in a triode configuration, consists of a CNT-column array cathode and an extraction gate with holes that are aligned concentrically with respect to the cylindrical CNT columns. In triode mode operation, cathode currents as large as ~420 μA have been emitted with an anode-to-gate current ratio of ~1.