Production of Hydronium Ion (H3O)+ and Protonated Water Clusters (H2O)nH+ after Energetic Ion Bombardment of Water Ice in Astrophysical Environments

2019 ◽  
Vol 123 (37) ◽  
pp. 8001-8008 ◽  
Author(s):  
R. Martinez ◽  
A. N. Agnihotri ◽  
Ph. Boduch ◽  
A. Domaracka ◽  
D. Fulvio ◽  
...  
Keyword(s):  
Water Clusters ◽  
Ion Bombardment ◽  
Water Ice ◽  
Hydronium Ion

Emission of ionic water clusters from water ice films bombarded by energetic projectiles

2004 ◽  
Vol 231-232 ◽  
pp. 72-77 ◽  
Author(s):  
Igor A. Wojciechowski ◽  
Uchkun Kutliev ◽  
Shixin Sun ◽  
Christopher Szakal ◽  
Nicholas Winograd ◽  
...  
Keyword(s):  
Water Clusters ◽  
Water Ice ◽  
Ice Films

scholarly journals Thermodynamics of homogeneous nucleation of ice particles in the polar summer mesosphere

2009 ◽  
Vol 9 (3) ◽  
pp. 965-971 ◽  
Author(s):  
A. Y. Zasetsky ◽  
S. V. Petelina ◽  
I. M. Svishchev
Keyword(s):  
Water Vapor ◽  
Homogeneous Nucleation ◽  
Water Clusters ◽  
Critical Size ◽  
Summer Temperature ◽  
Nano Particles ◽  
Vapor Density ◽  
Water Ice ◽  
Formation Pathway ◽  
Hexagonal Ice

Abstract. We present the hypothesis of homogeneous nucleation of ice nano-particles in the polar summer mesosphere. The nucleation of condensed phase is traced back to the first step on the formation pathway, which is assumed to be the transition of water vapor to amorphous cluster. Amorphous clusters then freeze into water ice, likely metastable cubic ice, when they reach the critical size. The estimates based on the equilibrium thermodynamics give the critical size (radius) of amorphous water clusters as about 1.0 nm. The same estimates for the final transition step, that is the transformation of cubic to hexagonal ice, give the critical size of about 15 nm at typical upper mesospheric conditions during the polar summer (temperature T=150 K, water vapor density ρvapor=109 cm−3).

Ejection of H2O, O2, H2 and H from water ice by 0.5–6 keV H+ and Ne+ ion bombardment

1985 ◽  
Vol 150 (1) ◽  
pp. 143-156 ◽  
Author(s):  
A. Bar-Nun ◽  
G. Herman ◽  
M.L. Rappaport ◽  
Yu. Mekler
Keyword(s):  
Ion Bombardment ◽  
Water Ice

scholarly journals Computing Binding Energies of Interstellar Molecules by Semiempirical Quantum Methods: Comparison Between DFT and GFN2 on Crystalline Ice

2021 ◽  
pp. 632-645
Author(s):  
Aurèle Germain ◽  
Marta Corno ◽  
Piero Ugliengo
Keyword(s):  
Gas Phase ◽  
Water Clusters ◽  
Binding Energies ◽  
Water Ice ◽  
Small Water ◽  
Adsorption Processes ◽  
Quantum Approach ◽  
Crystalline Water ◽  
Ordered Water ◽  
Grain Surface

AbstractInterstellar Grains (IGs) spread in the Interstellar Medium (ISM) host a multitude of chemical reactions that could lead to the production of interstellar Complex Organic Molecules (iCOMs), relevant in the context of prebiotic chemistry. These IGs are composed of a silicate-based core covered by several layers of amorphous water ice, known as a grain mantle. Molecules from the ISM gas-phase can be adsorbed at the grain surfaces, diffuse and react to give iCOMs and ultimately desorbed back to the gas phase. Thus, the study of the Binding Energy (BE) of these molecules at the water ice grain surface is important to understand the molecular composition of the ISM and its evolution in time. In this paper, we propose to use a recently developed semiempirical quantum approach, named GFN-xTB, and more precisely the GFN2 method, to compute the BE of several molecular species at the crystalline water ice slab model. This method is very cheap in term of computing power and time and was already showed in a previous work to be very accurate with small water clusters. To support our proposition, we decided to use, as a benchmark, the recent work published by some of us in which a crystalline model of proton-ordered water ice (P-ice) was adopted to predict the BEs of 21 molecules relevant in the ISM. The relatively good results obtained confirm GFN2 as the method of choice to model adsorption processes occurring at the icy grains in the ISM. The only notable exception was for the CO molecule, in which both structure and BE are badly predicted by GFN2, a real pity due to the relevance of CO in astrochemistry.

scholarly journals Plasma Emission from High Velocity Impacts of Microparticles Onto Water Ice

1991 ◽  
Vol 126 ◽  
pp. 375-378 ◽  
Author(s):  
R. Timmermann ◽  
E. Grün
Keyword(s):  
Experimental Study ◽  
Water Clusters ◽  
Plasma Emission ◽  
Outer Solar System ◽  
Gold Surfaces ◽  
Plasma Production ◽  
Water Ice ◽  
High Velocity Impacts ◽  
The Impact ◽  
Ion Species

AbstractCollisions of icy objects play a major role in the outer solar system. The purpose of this investigation is the experimental study of plasma production by dust impacts on icy surfaces. Impact speeds ranged from 3 to 60 km/s. It was found that the dominant ion species which were released are both positive and negative water clusters. The impact charge yield from icy surfaces is approximately a factor 100 below that from previously studied gold surfaces.

A Comparative Study of Secondary Ion Emission from Water Ice under Ion Bombardment by Au+, Au3+, and C60+

2009 ◽  
Vol 114 (12) ◽  
pp. 5468-5479 ◽  
Author(s):  
Xavier A. Conlan ◽  
John S. Fletcher ◽  
Nicholas P. Lockyer ◽  
John C. Vickerman
Keyword(s):  
Comparative Study ◽  
Ion Bombardment ◽  
Water Ice ◽  
Secondary Ion Emission ◽  
Ion Emission ◽  
Secondary Ion

Fundamental studies of the cluster ion bombardment of water ice

2006 ◽  
Vol 252 (19) ◽  
pp. 6526-6528 ◽  
Author(s):  
Christopher Szakal ◽  
Joseph Kozole ◽  
Nicholas Winograd
Keyword(s):  
Ion Bombardment ◽  
Water Ice ◽  
Cluster Ion

scholarly journals Thermodynamics of homogeneous nucleation of ice particles in the polar summer mesosphere

2008 ◽  
Vol 8 (4) ◽  
pp. 14497-14517 ◽  
Author(s):  
A. Y. Zasetsky ◽  
S. V. Petelina ◽  
I. M. Svishchev
Keyword(s):  
Water Vapor ◽  
Homogeneous Nucleation ◽  
Water Clusters ◽  
Critical Size ◽  
Summer Temperature ◽  
Nano Particles ◽  
Vapor Density ◽  
Water Ice ◽  
Formation Pathway ◽  
Hexagonal Ice

Abstract. We present the hypothesis of homogeneous nucleation of ice nano-particles in the polar summer mesosphere. The nucleation of condensed phase is traced back to the first step on the formation pathway, which is assumed to be the transition of water vapor to amorphous cluster. Amorphous clusters then freeze into water ice, likely metastable cubic ice, when they reach the critical size. The estimates based on the equilibrium thermodynamics give the critical size (radius) of amorphous water clusters as about 1.0 nm. The same estimates for the final transition step, that is the transformation of cubic to hexagonal ice, give the critical size of about 15 nm at typical upper mesospheric conditions during the polar summer (temperature T=150 K, water vapor density ρvapor=109 cm−3).

The Anomalous Fragmentation of Water Clusters at Ultrafast Impacts: An experimental and Theoretical Study

2014 ◽  
Vol 228 (4-5) ◽  
Author(s):  
Kfir Luria ◽  
Uzi Even ◽  
Wolfgang Christen ◽  
Klaus Rademann ◽  
Tamar Raz
Keyword(s):  
Water Clusters ◽  
Rare Gas ◽  
Theoretic Approach ◽  
Information Theoretic ◽  
Hydronium Ion ◽  
Sequential Loss ◽  
Residual Elements ◽  
Singly Charged ◽  
Gas Clusters ◽  
Information Theoretic Approach

AbstractExperimental results for the hypersonic impact of singly charged, mass selected, water clusters at a hard surface demonstrate cooling of the heated cluster by sequential loss of a water molecule. The trends in the experiment are most simply summarized as an evaporation. This behavior is in contrast to the shattering phenomena observed for rare gas clusters. The same information theoretic approach that predicted the shattering transition is fully consistent with the results for the water clusters. It shows that the relatively high binding energy per water monomer is the key reason for the anomalous fragmentation. The tetra coordinated oxygen atom in a cluster does however imply that the fragmentation is not a pure evaporation but has residual elements of a shattering transition. For water clusters the transition is broadened to span the finite range in energy between the onset of boiling and the energy when the solvation of the hydronium ion is over and it is bare.

Ion Beam Mixing of Ni-Ti Bilayered Thin Films

1985 ◽  
Vol 43 ◽  
pp. 290-291
Author(s):  
A. K. Rai ◽  
R. S. Bhattacharya ◽  
M. H. Rashid
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Amorphous Alloys ◽  
Ion Beam ◽  
Ion Bombardment ◽  
High Energy ◽  
Mixing Efficiency ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Binary Metal

Ion beam mixing has recently been found to be an effective method of producing amorphous alloys in the binary metal systems where the two original constituent metals are of different crystal structure. The mechanism of ion beam mixing are not well understood yet. Several mechanisms have been proposed to account for the observed mixing phenomena. The first mechanism is enhanced diffusion due to defects created by the incoming ions. Second is the cascade mixing mechanism for which the kinematicel collisional models exist in the literature. Third mechanism is thermal spikes. In the present work we have studied the mixing efficiency and ion beam induced amorphisation of Ni-Ti system under high energy ion bombardment and the results are compared with collisional models. We have employed plan and x-sectional veiw TEM and RBS techniques in the present work.

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