scholarly journals Sputtering Yields for C60and Au3Bombardment of Water Ice as a Function of Incident Kinetic Energy

2007 ◽  
Vol 79 (12) ◽  
pp. 4493-4498 ◽  
Author(s):  
Michael F. Russo ◽  
Christopher Szakal ◽  
Joseph Kozole ◽  
Nicholas Winograd ◽  
Barbara J. Garrison
Keyword(s):  
Kinetic Energy ◽  
Water Ice ◽  
Incident Kinetic Energy ◽  
Sputtering Yields

Osmosis: Characteristics of Liquid at an Interface

2006 ◽  
Author(s):  
Larry D. Howlett
Keyword(s):  
Kinetic Energy ◽  
Kinetic Theory ◽  
Vapor Pressure ◽  
Pressure Difference ◽  
Total Kinetic Energy ◽  
Universal Model ◽  
Vapor Pressure Difference ◽  
Water Ice ◽  
Speed Distribution

Many explanations for the movement of water across a membrane have been presented. One idea proposes that osmosis is the movement of water in response to a vapor pressure difference. It is difficult to accept this model for osmosis without a good understanding of the existence of a vapor in a liquid. We propose a model for a vapor in a liquid. The model is based upon the kinetic theory of gas and Maxwell's predicted speed distribution. Since vapor pressure and total kinetic energy are both expressions of the energy of a gas, we compare the model to published values of vapor pressure for water, ice, and several other liquids. Based upon this limited comparison, it appears that this model may be a universal model for the continuous existence of a vapor in a liquid or a solid.

Characteristics of the projectile and target fragments produced in 84Kr36 — emulsion interaction at 1GeV per nucleon

2020 ◽  
Vol 29 (09) ◽  
pp. 2050077
Author(s):  
S. Kumar ◽  
M. K. Singh ◽  
R. K. Jain ◽  
V. Singh
Keyword(s):  
Kinetic Energy ◽  
Nuclear Emulsion ◽  
Emission Characteristics ◽  
Fragmentation Parameter ◽  
Different Types ◽  
Emission Behavior ◽  
Singly Charged ◽  
Doubly Charged ◽  
Incident Kinetic Energy

In the present analysis, we have focused on the emission characteristics of the projectile and target fragments produced from the interaction of [Formula: see text]Kr with nuclear emulsion at 1 A GeV. We have studied the variation of the fragmentation parameter for singly charged [Formula: see text], doubly charged [Formula: see text], lower multiple-charged [Formula: see text]–[Formula: see text], medium multiple-charged [Formula: see text]–[Formula: see text] and higher multiple-charged [Formula: see text], projectile fragments with respect to mass of the projectile and found that they are showing the different behaviors for different projectile fragments. We have also studied the emission behavior of shower particles, with respect to the black and gray particles. The present studies show that the production of shower particles strongly depends on the incident kinetic energy of the projectile and also depending on the interaction of the different types of target nuclei of nuclear emulsion.

scholarly journals Non-thermal desorption of complex organic molecules

2020 ◽  
Vol 634 ◽  
pp. A103
Author(s):  
E. Dartois ◽  
M. Chabot ◽  
A. Bacmann ◽  
P. Boduch ◽  
A. Domaracka ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Gas Phase ◽  
Organic Molecules ◽  
Solid Phase ◽  
Bulk Composition ◽  
Cosmic Ray ◽  
Water Ice ◽  
Sputtering Yield ◽  
Sputtering Yields ◽  
Complex Organic

Aims. Methanol ice is embedded in interstellar ice mantles present in dense molecular clouds. We aim to measure the sputtering efficiencies starting from different ice mantles of varying compositions experimentally, in order to evaluate their potential impact on astrochemical models. The sputtering yields of complex organic molecules is of particular interest, since few mechanisms are efficient enough to induce a significant feedback to the gas phase. Methods. We irradiated ice film mixtures made of methanol and carbon dioxide of varying ratios with swift heavy ions in the electronic sputtering regime. We monitored the evolution of the infrared spectra as well as the species released to the gas phase with a mass spectrometer. Methanol (12C) and isotopically labelled 13C-methanol were used to remove any ambiguity on the measured irradiation products. Results. The sputtering of methanol embedded in carbon dioxide ice is an efficient process leading to the ejection of intact methanol in the gas phase. We establish that when methanol is embedded in a carbon-dioxide-rich mantle exposed to cosmic rays, a significant fraction (0.2–0.3 in this work) is sputtered as intact molecules. The sputtered fraction follows the time-dependent bulk composition of the ice mantle, the latter evolving with time due to the radiolysis-induced evolution of the bulk. If methanol is embedded in a carbon dioxide ice matrix, as the analyses of the spectral shape of the CO2 bending mode observations in some lines of sight suggest, the overall methanol sputtering yield is higher than if embedded in a water ice mantle. The sputtering is increased by a factor close to the dominant ice matrix sputtering yield, which is about six times higher for pure carbon dioxide ice when compared to water ice. These experiments are further constraining the cosmic-ray-induced ice mantle sputtering mechanisms important role in the gas-phase release of complex organic molecules from the interstellar solid phase.

Collision dynamics of cytosine under proton irradiation

2021 ◽  
pp. 2150242
Author(s):  
Chaoyi Qian ◽  
Zhiping Wang ◽  
Xuefen Xu ◽  
Yanbiao Wang ◽  
Fengshou Zhang
Keyword(s):  
Kinetic Energy ◽  
Incident Energy ◽  
Density Functional ◽  
Collision Dynamics ◽  
Electronic Density ◽  
Functional Theory ◽  
Scattering Angle ◽  
Valence Electrons ◽  
Damage Process ◽  
Incident Kinetic Energy

In the framework of the time-dependent density-functional theory, applied to valence electrons, coupled non-adiabatically to molecular dynamics of ions, the collision dynamics of cytosine impacted by proton is studied. We especially focus on the effect of the collision orientations on the damage of cytosine by choosing two collision orientations taking the oxygen atom on the double bond CO as the collision site with the incident energy of proton ranging from 150 eV to 1000 eV. First, two collision dynamical processes are explored by analyzing the molecular ionization, the ionic position and the kinetic energy, the energy loss of proton and the electronic density evolution. The results show that the damage process of cytosine induced by proton impact is mainly the capture of electrons by proton, the departments of ions and groups as well as the opening of ring. It is found that the orientation has little effect on the loss of the kinetic energy of proton, which is about 21.5[Formula: see text] of the incident energy of proton. Although the scattering angle [Formula: see text] has a polynomial relationship with [Formula: see text] in both cases, it is greatly affected by the orientation. When [Formula: see text] eV, the scattering angle of proton colliding with O along the x-axis is greater than that of proton colliding with O along the y-axis. The orientation also has a great effect on the mass distribution of the fragments and the fragmentation route. When proton moves along the x-axis, the fragmentation route is that O leaves the cytosine and the rest keeps on vibration, while products are not only related to the incident kinetic energy, but also show diversity when proton moves along the y-axis.

Dissociative Chemisorption at Hyperthermal Energies: Benchmark Studies in Group IV Systems

1995 ◽  
Vol 388 ◽  
Author(s):  
L.-Q. Xia ◽  
M. E. Jones ◽  
N. Maity ◽  
S. E. Roadman ◽  
J. R. Engstrom†
Keyword(s):  
Kinetic Energy ◽  
Group Iv ◽  
Reaction Probability ◽  
Angle Of Incidence ◽  
Dissociative Chemisorption ◽  
Reaction Conditions ◽  
Molecular Beam Scattering ◽  
Supersonic Molecular Beam ◽  
Universal Relationship ◽  
Incident Kinetic Energy

AbstractWe present a review of our recent work concerning supersonic molecular beam scattering of thin film precursors from the Si(100) and Si(111) surfaces. Both SiH4 and Si2H6 exhibit translationally activated dissociation channels at sufficiently high incident kinetic energies, (E┴) 0.5 eV. the dominant variables under our reaction conditions are the incident kinetic energy and the angle of incidence, whereas mean internal energy and substrate temperature play relatively minor roles. the former two variables couple to produce a universal relationship between the reaction probability and a scaled kinetic energy given by (E┴) = Eі[(l-Δ)cos2θі + 3Δsin2θі], where θі is the angle of incidence, a is a corrugation parameter, and 0 ≤ Δ ≤ 1. IN addition to the reaction probability, the reaction mechanism for Si2H6 is also dependent upon incident kinetic energy and surface structure, where a SiH4(g) production channel is observed on the Si(111)-(7x7) surface at low to moderate incident kinetic energies. the reactions of SiH3CH3 and PH3 provide convenient comparative examples. Methylsilane, reacting on a β-SiC surface, exhibits a translationally activated dissociation channel, similar to what is observed for SiH4 and Si2H6. Phosphine, on the other hand, exhibits the characteristics of trapping, precursor-mediated dissociative chemisorption. these results act to underscore the important role played by the frontier orbital topology, even at hyperthermal incident kinetic energies.

Light Particle Production in Spallation Reactions Induced by Protons of 0.8-2.5 GeV Incident Kinetic Energy

2002 ◽  
Vol 39 (sup2) ◽  
pp. 262-265 ◽  
Author(s):  
Claus-Michael Herbach ◽  
Andreas Böhm ◽  
Michael Enke ◽  
Detlef Filges ◽  
Joel Galin ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Particle Production ◽  
Light Particle ◽  
Spallation Reactions ◽  
Incident Kinetic Energy

Ion-Beam-Induced Modifications of Thin Films: Growth Simulations

1987 ◽  
Vol 93 ◽  
Author(s):  
Karl-Heinz Müller
Keyword(s):  
Kinetic Energy ◽  
Film Growth ◽  
Ion Beam ◽  
Film Surface ◽  
Energetic Ions ◽  
Film Microstructure ◽  
Deposition Processes ◽  
Incident Kinetic Energy ◽  
Cluster Beam Deposition ◽  
Beam Deposition

ABSTRACTIf the thermal adatom mobility is limited during film growth, the kinetic energy delivered to the film surface by arriving species is the key parameter which determines the resulting film microstructure and properties. Kinetic models and growth simulations of nonequilibrium film growth have been used to study the influence of incident kinetic energy of adatoms and energetic ions on the film microstructure, microporosity, density, stoichiometry and epitaxy. Deposition processes like vapor, sputter, ion-assisted and ionized cluster beam deposition, could be examined in detail with particular emphasis on optical coatings. The theoretical descriptions used are based on the solid-gas, thermal spike, collision cascade and molecular dynamics model.

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