A double-cusp type electrostatic analyzer for high-cadence solar-wind suprathermal ion observations

2018 ◽  
Vol 89 (11) ◽  
pp. 114503
Author(s):  
Keiichi Ogasawara ◽  
Frédéric Allegrini ◽  
Mihir I. Desai ◽  
Robert W. Ebert ◽  
Stephen A. Fuselier ◽  
...  
Keyword(s):  
Solar Wind ◽  
Electrostatic Analyzer ◽  
High Cadence

Electrostatic analyzer design for solar wind proton measurements with high temporal, energy, and angular resolutions

2017 ◽  
Vol 122 (2) ◽  
pp. 1439-1450 ◽  
Author(s):  
Antoine Cara ◽  
Benoit Lavraud ◽  
Andrei Fedorov ◽  
Johan De Keyser ◽  
Rossana DeMarco ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Wind Proton ◽  
Electrostatic Analyzer

Evolution of the electron velocity distribution under the presence of whistler waves in the solar wind (high-cadence Solar Orbiter observations)

2021 ◽  
Author(s):  
Laura Bercic ◽  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Velocity Distribution ◽  
Electron Velocity ◽  
The Sun ◽  
Momentum Exchange ◽  
Whistler Waves ◽  
Electro Magnetic ◽  
Halo Population ◽  
High Cadence

<div> <div> <div> <p>The solar coronal plasma which escapes the Sun’s gravity and expands through our solar system is called the solar wind. It consists mainly of electrons and protons, carries the Sun’s magnetic field and, at most heliocentric distances, remains weakly-collisional. Due to their small mass, the solar wind electrons have much higher thermal velocity than their positively charged counterpart, and play an important role in the solar wind energetics by carrying the heat flux away from the Sun. Their velocity distribution functions (VDFs) are complex, usually modeled by three components. While the majority of electrons belong to the low-energetic thermal Maxwellian core population, some reach higher velocities, forming either the magnetic field aligned strahl population, or an isotropic high-energy halo population. This shape of the electron VDF is a product of the interplay between<br>Coulomb collisions, adiabatic expansion, global and local electro-magnetic fields and turbulence.<br>In this work we focus on the effects of local electro-magnetic wave activity on electron VDF, taking advantage of the early measurements made by the novel heliospheric Solar Orbiter mission. The high- cadence sampling of 2-dimensional electron VDFs by the electrostatic analyser SWA-EAS, together with the EM wave data collected by the seach-coil magnetometers and electric-field antennas, part of</p> </div> </div> </div><div> <div> <div> <p>the RPW instrument suit, allow a direct investigation of the wave-particle energy and momentum exchange. We present the evolution of the electron VDF in the presence of quasi-parallel and oblique whistler waves, believed to be responsible for scattering the strahl and creating the halo population (Verscharen et al. 2019; Micera et al. 2020).</p> </div> </div> </div>

Open-ended, high cadence, Kp-like geomagnetic index Hp

2020 ◽  
Author(s):  
Jürgen Matzka ◽  
Guram Kervalishvili ◽  
Jan Rauberg ◽  
Claudia Stolle ◽  
Yosuke Yamazaki
Keyword(s):  
Solar Wind ◽  
Frequency Distribution ◽  
Temporal Resolution ◽  
Geomagnetic Activity ◽  
Space Weather ◽  
Energy Input ◽  
Geomagnetic Index ◽  
High Cadence

<p>An open-ended, high cadence, Kp-like geomagnetic index, called Hp index, is developed within the H2020 project SWAMI (Space Weather Atmosphere Models and Indices). The traditional Kp index is an excellent measure for energy input by the solar wind and is widely used in space weather science and applications. The new planetary index Hp resembles the Kp index by having a similar derivation scheme and a nearly identical frequency distribution of index values. Hp is available from 1995 onward with different time resolutions, e.g., 30 minutes and 60 minutes, and thus provides a higher temporal resolution than the 3-hourly Kp index. Additionally, events with Hp > 9- were further subdivided using an open-ended scale (9o, 9+, 10-, 10o, 10+, 11-, ...) to represent the highest levels of geomagnetic activity with higher resolution.</p>

scholarly journals Whistler instability driven by the sunward electron deficit in the solar wind: High-cadence Solar Orbiter observations

2021 ◽  
Author(s):  
Laura Bercic ◽  
Daniel Verscharen ◽  
Christopher Owen ◽  
Lucas Colomban ◽  
Matthieu Kretzschmar ◽  
...  
Keyword(s):  
Solar Wind ◽  
High Cadence

scholarly journals Whistler instability driven by the sunward electron deficit in the solar wind. High-cadence Solar Orbiter observations

2021 ◽  
Author(s):  
L. Bercic ◽  
D. Verscharen ◽  
C. J. Owen ◽  
L. Colomban ◽  
M. Kretzschmar ◽  
...  
Keyword(s):  
Solar Wind ◽  
High Cadence

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

Quantitative surface damage studies by H.R.E.M.

1989 ◽  
Vol 47 ◽  
pp. 632-633
Author(s):  
S. R. Singh ◽  
H. J. Fan ◽  
L. D. Marks
Keyword(s):  
Solar Wind ◽  
Quantitative Analysis ◽  
Surface Science ◽  
Surface Damage ◽  
Space Environment ◽  
Oxygen Desorption ◽  
The Past ◽  
Diffusion Controlled ◽  
Original Observation ◽  
Substantial Interest

Since the original observation that the surfaces of materials undergo radiation damage in the electron microscope similar to that observed by more conventional surface science techniques there has been substantial interest in understanding these phenomena in more detail; for a review see. For instance, surface damage in a microscope mimics damage in the space environment due to the solar wind and electron beam lithographic operations.However, purely qualitative experiments that have been done in the past are inadequate. In addition, many experiments performed in conventional microscopes may be inaccurate. What is needed is careful quantitative analysis including comparisons of the behavior in UHV versus that in a conventional microscope. In this paper we will present results of quantitative analysis which clearly demonstrate that the phenomena of importance are diffusion controlled; more detailed presentations of the data have been published elsewhere.As an illustration of the results, Figure 1 shows a plot of the shrinkage of a single, roughly spherical particle of WO3 versus time (dose) driven by oxygen desorption from the surface.

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