Investigation of Diamond-like Carbon Charge State Conversion Surfaces for Low Energy Neutral Atom Imaging Detectors in Space Applications
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Interplanetary satellite missions and also satellites orbiting the Earth carry instruments to measure fluxes of neutral atoms, which are plasma key parameters for the investigation of the planets' atmospheres. Neutral atoms entering the mass-spectrometry instrument have to be ionized to be able to guide them using electric and magnetic fields with intent to determine energy and velocity of the atoms and finally their mass. For low energy neutral atoms, the ionization process can be realized by implementing a charge state conversion surface, where-on the atoms are scattered in an angle of grazing incidence and getting ionized.The objective of this work is the characterization and analysis of two diamond-like carbon surface samples by measuring and determining ionization efficiencies and scattering properties and therefore their functionality as charge state conversion surfaces.First, a chemical vapor deposition (CVD) diamond sample is investigated. Furthermore the CVD diamond is compared to another diamond--like carbon surface manufactured by pulsed laser deposition (PLD) technique. All measurements have been accomplished at the ILENA (Imager for Low Energy Neutral Atoms) facility at the Physics Institute, University of Bern in the Department of Space Research and Planetary Sciences.It is discovered that the CVD surface gets electrostatically charged upon scattering of atomic ions. Though this charging effects, a qualitative characterization of the surface can be made. It is shown that the ionization efficiencies of the CVD and the PLD diamond surface are of comparable quality, where on the contrary the scattering properties of the CVD diamond charge state conversion surface are much better. It still has to be investigated in future experiments, if this brilliant scattering properties are due to charging effects or can be assigned to the very smooth surface of the CVD diamond surface.
Place, publisher, year, edition, pages
2012. , 102 p.
Physics Chemistry Maths, Space Instrumentation, Conversion Surface, ENA, Neutral Atom Imaging
Fysik, Kemi, Matematik
IdentifiersURN: urn:nbn:se:ltu:diva-58268Local ID: ed994b1d-e98e-4cda-ad3d-c7e1e8083081OAI: oai:DiVA.org:ltu-58268DiVA: diva2:1031656
Subject / course
Student thesis, at least 30 credits
Space Engineering, master's level
Validerat; 20120112 (anonymous)2016-10-042016-10-04Bibliographically approved