Imaging of Ganymede through Energetic Neutral Atoms sputtered/backscattered from the surface

Brightness asymmetries on the surface of Ganymede are thought to be caused by ion impact from Jovian co-rotating plasma. The Jovian Neutrals Analyzer instrument onboard the JUICE spacecraft will help investigate this theory by yielding a map of ion precipitation at the surface of Ganymede through the observation of low-energy Energetic Neutral Atoms (ENAs) (10 eV to 3300 eV) sputtered or backscattered by the Jovian plasma. In order to optimize JNA operations planning at Ganymede, we estimate the expected energy distribution of ENAs caused by the impacting Jovian plasma. As an input, we use results from a three dimensional hybrid plasma simulation, which gives us the energy distribution of precipitating H+, O++ and S+++ at the surface of Ganymede. We then calculate the ENA yield using respectively Fam&#224;&#8217;s model (Fam&#224;, 2008) for the sputtering yield of water ice and Thompson-Sigmund&#8217;s model (Sigmund, 1969) for electronic sputtering to get the energy distribution of the ENAs.

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What Does Our Heliosphere Look Like in Energetic Neutral Atoms? Some Recommendations for a Low-Energy ENA Camera Onboard the Interstellar Probe

10.1002/essoar.10500565.1 ◽

2019 ◽

Author(s):

André Galli ◽

Peter Wurz ◽

Jens Kleimann ◽

Horst Fichtner ◽

Yoshifumi Futaana ◽

...

Keyword(s):

Low Energy ◽

Neutral Atoms ◽

Energetic Neutral Atoms ◽

Interstellar Probe

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Can we use graphene as a conversion surface for a neutral particle detector?

10.5194/egusphere-egu2020-9593 ◽

2020 ◽

Author(s):

Alexander Grigoriev ◽

Andrei Fedorov ◽

Nicolas André

Keyword(s):

Secondary Electron ◽

Grazing Angle ◽

Secondary Electron Emission ◽

Incident Beam ◽

Particle Energy ◽

Low Energy ◽

Wafer Surface ◽

Neutral Atoms ◽

Energetic Neutral Atoms ◽

First Case

An important technique of modern space plasma diagnostics is a detection and imaging of low energy (below 10 keV) energetic neutral atoms (ENA). Any space mission devoted to study of the planetary plasma environments, planetary magnetospheres and heliosphere boundaries, needs a low energy ENA imaging sensor in its payload list. A common approach to the ENA detection/imaging is to make energetic neutral atoms glance a high quality conductive surface and either produce a secondary electron, or produce a positive or negative reflection ion. In the first case we can collect and detect the yielded secondary electron and generate a start signal. The reflected neutral atom can be directed to another surface with a high secondary electron yield. Thus we can measure a time-of-flight of the reflected particle to get its velocity. In the second case we can analyze the reflected ion in an electrostatic analyzer to get the particle energy.Many types of conversion surfaces have been investigated over last decades in order to optimize an ENA sensor properties. We investigated properties of a thin layer of graphene applied to a silicon wafer surface. The experimental setup consisted of a secondary electron detector, neutral/ions separator and a high resolution particle imager. We used an incident He beam with energy of 200 eV - 3000 eV. We obtained a secondary electron emission, particle reflection efficiency, scattering properties, and a positive ion production rate as a function of the incident beam energy and the grazing angle. The experiment results show that 1) Graphene is a good source of secondary electrons even for low energy incident particles; 2) ENA scatter from the graphene surface similar to other surface types; 3) Graphene does not convert incident ENA to positive ions, especially for high grazing angles.

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Emission of energetic neutral atoms from water ice under Ganymede surface-like conditions

Icarus ◽

10.1016/j.icarus.2015.12.043 ◽

2016 ◽

Vol 269 ◽

pp. 91-97 ◽

Cited By ~ 3

Author(s):

Martin Wieser ◽

Yoshifumi Futaana ◽

Stas Barabash ◽

Peter Wurz

Keyword(s):

Neutral Atoms ◽

Water Ice ◽

Energetic Neutral Atoms

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Electron Stimulated Desorption by Low Energy Ion Impact

Physica Scripta ◽

10.1088/0031-8949/1983/t6/016 ◽

1983 ◽

Vol T6 ◽

pp. 104-105 ◽

Cited By ~ 4

Author(s):

J Möller ◽

M Neumann ◽

W Heiland

Keyword(s):

Low Energy ◽

Ion Impact ◽

Electron Stimulated Desorption

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Energetic neutral atoms at Mars 2. Imaging of the solar wind-Phobos interaction

Journal of Geophysical Research Atmospheres ◽

10.1029/2001ja000328 ◽

2002 ◽

Vol 107 (A10) ◽

Cited By ~ 17

Author(s):

Alessandro Mura

Keyword(s):

Solar Wind ◽

Neutral Atoms ◽

Energetic Neutral Atoms

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Low-energy ferroelectric–paraelectric phase transitions of three-dimensional A(II)B(I)X3-type perovskite ferroelectrics: How to realize high phase transition temperatures

APL Materials ◽

10.1063/5.0035199 ◽

2021 ◽

Vol 9 (1) ◽

pp. 010704

Author(s):

Jie Bie ◽

Wei Fa ◽

Shuang Chen

Keyword(s):

Phase Transition ◽

Phase Transitions ◽

Paraelectric Phase ◽

Three Dimensional ◽

Low Energy ◽

Transition Temperatures ◽

Phase Transition Temperatures ◽

High Phase

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Molecular Dynamics Study of Ion Impact Phenomena and Compressive Stress in Thin Films

MRS Proceedings ◽

10.1557/proc-317-497 ◽

1993 ◽

Vol 317 ◽

Cited By ~ 1

Author(s):

N.A. Marks ◽

P. Guan ◽

D.R. Mckenzie ◽

B.A. PailThorpe

Keyword(s):

Molecular Dynamics ◽

Three Dimensional ◽

Carbon Films ◽

Loss Mechanism ◽

Ion Energy ◽

Lennard Jones ◽

Impact Phenomena ◽

Ion Impact ◽

Dynamics Simulations ◽

The Impact

ABSTRACTMolecular dynamics simulations of nickel and carbon have been used to study the phenomena due to ion impact. The nickel and carbon interactions were described using the Lennard-Jones and Stillinger-Weber potentials respectively. The phenomena occurring after the impact of 100 e V to 1 keV ions were studied in the nickel simulations, which were both two and three-dimensional. Supersonic focussed collision sequences (or focusons) were observed, and associated with these focusons were unexpected sonic bow waves, which were a major energy loss mechanism for the focuson. A number of 2D carbon films were grown and the stress in the films as a function of incident ion energy was Measured. With increasing energy the stress changed from tensile to compressive and reached a maximum around 50 eV, in agreement with experiment.

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