Effect of long duration UV irradiation on diamondlike carbon surfaces in the presence of a hydrocarbon gaseous atmosphere

Abstract

Measurements of the effect of long duration UV irradiation (up to 2905 min) of flight quality diamondlike carbon charge state conversion surfaces for application in space research in the presence of a hydrocarbon atmosphere were done. An isopropanol atmosphere was used for simulating the hydrocarbon gaseous environment for an instrument on a satellite in space. Charge state conversion surfaces are used in neutral particle sensing instruments where neutral atoms have to be ionized prior to the analysis. A narrow-band (126±5 nm) discharge lamp and a broad-band deuterium lamp (112–370 nm) were used as sources of UV radiation. The UV irradiation of a surface results in the desorption of some volatiles present on the surface and the decomposition of others. Desorption of volatiles, mostly water, is observed for both UV sources. The decomposition of the hydrocarbons and the subsequent build-up of a hydrocarbonaceous layer is only observed for the broad-band UV lamp, which is more representative for the space environment. Unfortunately, the hydrocarbonaceous layer cannot be removed thermally, i.e., it is permanent, and causes a degradation of the performance of the charge state conversion surfaces. With the present measurements we can quantify the UV influence at which the degradation of the conversion surfaces becomes noticeable.

CAMAM: A Miniature Laser Ablation Ionisation Mass Spectrometer and Microscope‐Camera System for In Situ Investigation of the Composition and Morphology of Extraterrestrial Materials

“…Laser desorption studies of glycine and toluene deposited on solid surfaces: LMS can be used to investigate molecular compounds deposited on solid surfaces (Riedo et al 2010). For such investigations, laser power densities about thousand times lower compared with ablation conditions have to be applied.…”

Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer

“…Detection of elements and their isotopes to differentiate between biotic an abiotic materials can be investigated by currently available miniature mass spectrometric instruments (Brinckerhoff et al, 2000;Rohner et al, 2003Rohner et al, , 2004Managadze et al, 2010). Performance studies of a miniature laser ablation/ionization time-of-flight mass spectrometer (LMS) system developed for space research in our group have been reported in several recent publications (Riedo et al, 2010(Riedo et al, , 2013a(Riedo et al, , 2013bTulej et al, , 2014Neuland et al, 2014;Grimaudo et al, 2015). Laser ablation/ionization mass spectrometry allows for highly sensitive detection of almost all elements and isotopes with their concentrations down to tens of parts per billion at significantly better than unit mass resolution.…”

Characterization of the gaseous spacecraft environment of Rosetta by ROSINA

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