Book/Report

FZJ-2018-03402

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Chemische Probleme bei Kometensimulations-Experimenten KOSI

Roessler, K. (Corresponding author)FZJ*

1991
Forschungszentrum Jülich GmbH Zentralbibliothek Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18864

Report No.: Juel-2446

Abstract: The report informs on preparation of analog material for the comet simulation experiments KOSI in the big Space Simulator Chamber of Institut für Raumsimulation DLR-Köln, and the preceding laboratory studies in Jülich. In three experiments KOSI-5 to 7, "organic solids" were introduced: CH$_{3}$OH, charcoal, and kerogen. The cryohandling in glove boxes with LN$_{2}$ baths and the analysis of unirradiated standard and insolated main samples are described. Visual inspection of the interior of the analogs, analysis of concentration profiles of the components and test of material strength by drilling revealed an interesting phenomenon: Volatile components such as CO$_{2}$ or CH$_{3}$OH do not only diffuse outoff the mineral-ice sample, but also into its colder interior. This inward diffusion leads to enrichment layers characterized by formation of brilliant crystallites or solidification to inner crusts. These layers are arranged in a way that the more volatile compounds recrystallize deeper in the interior, such as in a kind of "thermochromatography". The solidification by condensation in the interior is the stronger, the higher the content of solid material (minerals, carbon, kerogen) and negligible in pure H$_{2}$O-CO$_{2}$-ice samples. A VUV-source is applied in the space simulator to complete the light spectrum with respect to the photons with kinetic energies up to 10 eV which are characteristic for the real solar spectrum but do not exist in the light from Xenon-lamps which constitute the source for the artifical sun in KOSI. Single constituents of the analog samples are tested for their behaviour during photolysis in a small vacuum chamber in KFA Jülich. Optical spectroscopy data of some of the solid constituents (olivine, montmorillonite, kerogen) of the KOSI-7 material is reported for many spectroscopic methods (transmission, reflexion, FTIR, FTRAMAN, photoacoustic detection etc.).

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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