A Cryogenic Ice Setup To Simulate Carbon Atom Reactions In Interstellar Ices

A three atomic beam line system, including the new C-atom source introduced here. The three atomic beam lines are capable of generating, H/D, N, O, and C-atoms, in addition to small radicals (e.g., OH, NH). It also contains two regular deposition lines. Both, pre-deposition and co-deposition experiments can be performed. RAIRS and TPD-QMS are used as diagnostic tools.

The design, implementation, and performance of a customized carbon atom beam source for the purpose of investigating solid-state reaction routes in interstellar ices in molecular clouds are discussed.

The source is integrated into an existing ultrahigh vacuum setup, SURFace REaction SImulation DEvice (SURFRESIDE2), which extends this double atom (H/D, O, and N) beamline apparatus with a third atom (C) beamline to a unique system that is fully suited to explore complex organic molecule solid-state formation under representative interstellar cloud conditions.

The parameter space for this system is discussed, which includes the flux of the carbon atoms hitting the ice sample, their temperature, and the potential impact of temperature on ice reactions. Much effort has been put into constraining the beam size to within the limits of the sample size with the aim to reduce carbon pollution inside the setup. How the C-atom beam performs is quantitatively studied through the example experiment, C + 18O2, and supported by computationally-derived activation barriers. The potential for this source to study the solid-state formation of interstellar complex organic molecules through C-atom reactions is discussed.

D. Qasim, M.J.A. Witlox, G. Fedoseev, K.-J. Chuang, T. Banu, S.A. Krasnokutski, S. Ioppolo, J. Kastner, E.F. van Dishoeck, H. Linnartz
(Submitted on 14 Apr 2020)
Comments: Accepted for publication in Review of Scientific Instruments
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
Cite as: arXiv:2004.06681 [astro-ph.SR] (or arXiv:2004.06681v1 [astro-ph.SR] for this version)
Submission history
From: Danna Qasim
[v1] Tue, 14 Apr 2020 17:34:10 UTC (2,579 KB)
Astrobiology, Astrochemistry

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