scholarly journals Simultaneously Formed Wedge‐Like Structures of Different Ion Species Deep in the Inner Magnetosphere

2020 ◽  
Vol 125 (12) ◽  
Author(s):  
Jie Ren ◽  
Q. G. Zong ◽  
C. Yue ◽  
X. Z. Zhou ◽  
S. Y. Fu ◽  
...  
Keyword(s):  
Inner Magnetosphere ◽  
Ion Species

Tracking the Differential Transport and Acceleration of Nitrogen and Oxygen Ions from the Terrestrial Ionosphere to the Inner Magnetosphere

2020 ◽  
Author(s):  
Raluca Ilie ◽  
Mei-Yun Lin ◽  
Alex Glocer ◽  
Muhammad Fraz Bashir
Keyword(s):  
Ring Current ◽  
High Energy ◽  
Transport Processes ◽  
Hot Electron ◽  
Polar Wind ◽  
Inner Magnetosphere ◽  
Oxygen Ions ◽  
Terrestrial Magnetosphere ◽  
Nitrogen Ions ◽  
Ion Species

<p>The presence of heavy ions has a profound impact on the temporal response of the magnetosphere to internal and external forcing, and plays a key role in plasma entry and transport processes within the terrestrial magnetosphere.</p><p>Numerous studies focused on the transport and energization of O<sup>+</sup> through the ionosphere-magnetosphere system; however, relatively few have considered the contribution of N<sup>+</sup> to the near-Earth plasma, even though past observations have established that N<sup>+</sup> is a significant ion species in the ionosphere and its presence in the magnetosphere is significant. In spite of only 12% mass difference, N<sup>+ </sup>and O<sup>+</sup> have different ionization potentials, scale heights and charge exchange cross sections. The latter, together with the geocoronal density distribution, plays a significant role in the formation of ENAs, which in turn controls the energy budget of the inner magnetosphere, and the overall loss of the ring current. Therefore, the outflow of N<sup>+</sup> from the ionosphere, in addition to that of O<sup>+</sup>, affects the global structure and properties of the current sheet, the mass loading of the magnetosphere, and it leads to changes in the local properties of the plasma, which in turn can influence waves propagation.</p><p> </p><p>This study involves an integrated computational view of geospace, that solves and tracks the evolution of all relevant ion species, to systematically assess their regional and global influence on the various loss and acceleration mechanisms operating throughout the terrestrial magnetosphere. We employ the newly developed Seven Ion Polar Wind Outflow Model (7iPWOM), which in addition to tracking the transport of H<sup>+</sup>, He<sup>+</sup> and O<sup>+</sup>, now solves for the heating and transport of N<sup>+</sup>, N<sub>2</sub><sup>+</sup>, NO<sup>+</sup> and O<sub>2</sub><sup>+ </sup>in Earth’s polar wind. The 7iPWOM is coupled with a two-stream model of superthermal electrons (GLobal airglow, or GLOW) to account for the attenuated radiation, electron beam energy dissipation, and secondary electron impact. We show that during various solar conditions, the polar wind outflow solution using 7iPWOM improves significantly when compared with OGO observations.</p><p> </p><p>In addition, numerical simulations using the kinetic drift Hot Electron Ions Drift Integrator (HEIDI) model suggest that the contribution of outflowing N<sup>+ </sup>to the ring current dynamics is significant, as the presence of N<sup>+</sup>alters the development and the decay rate of the ring current. Electron transfer collisions are far more efficient at removing N<sup>+</sup> the system, compared with the removal of O<sup>+</sup> ions. Synthetic TWINS-like mass separated ENA images show that the presence on nitrogen ions in the ring current, even in small amounts, significantly alters the ENA fluxes, and the peak of oxygen ENA fluxes can vary for up to an order of magnitude, depending on the magnetosphere composition. These findings can explain recent observations of faster than expected decay of high energy oxygen ions, as measured by the RBSPICE instrument on board of the Van Allen Probe spacecraft. We speculate that the abundance of oxygen has been mis-estimated, as it is likely that some of the oxygen measurements to actually be include comparable abundances of nitrogen ions.</p>

Modification of Low ĸ Materials for ULSI Multilevel Interconnects by Ion Implantation

2002 ◽  
Vol 716 ◽  
Author(s):  
Alok Nandini ◽  
U. Roy ◽  
A. Mallikarjunan ◽  
A. Kumar ◽  
J. Fortin ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Ion Implantation ◽  
Dielectric Materials ◽  
Dramatic Improvement ◽  
Force Microscopy ◽  
Low Dielectric ◽  
Quantitative Measurements ◽  
Hardness Increase ◽  
Xerogel Films ◽  
Ion Species

AbstractThin films of low dielectric constant (κ) materials such as Xerogel (ĸ=1.76) and SilkTM (ĸ=2.65) were implanted with argon, neon, nitrogen, carbon and helium with 2 x 1015 cm -2 and 1 x 1016 cm -2 dose at energies varying from 50 to 150 keV at room temperature. In this work we discuss the improvement of hardness as well as elasticity of low ĸ dielectric materials by ion implantation. Ultrasonic Force Microscopy (UFM) [6] and Nano indentation technique [5] have been used for qualitative and quantitative measurements respectively. The hardness increased with increasing ion energy and dose of implantation. For a given energy and dose, the hardness improvement varied with ion species. Dramatic improvement of hardness is seen for multi-dose implantation. Among all the implanted ion species (Helium, Carbon, Nitrogen, Neon and Argon), Argon implantation resulted in 5x hardness increase in Xerogel films, sacrificing only a slight increase (∼ 15%) in dielectric constant.

The Inner Magnetosphere Imager mission

1993 ◽  
Author(s):  
Les Johnson ◽  
Melody Herrmann
Keyword(s):  
Inner Magnetosphere

Access of plasma sheet ions to the inner magnetosphere

2001 ◽  
Author(s):  
Paul Rothwell ◽  
William Burke ◽  
Carl-Gunne Falthammar
Keyword(s):  
Plasma Sheet ◽  
Inner Magnetosphere

scholarly journals Benchmark of a new multi-ion-species collision operator for δf Monte Carlo neoclassical simulation

2020 ◽  
Vol 255 ◽  
pp. 107249 ◽  
Author(s):  
Shinsuke Satake ◽  
Motoki Nataka ◽  
Theerasarn Pianpanit ◽  
Hideo Sugama ◽  
Masanori Nunami ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Collision Operator ◽  
Ion Species

scholarly journals Single-shot imaging of surface molecular ionization in nanosystems

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fenghao Sun ◽  
Hui Li ◽  
Shanshan Song ◽  
Fei Chen ◽  
Jiawei Wang ◽  
...  
Keyword(s):  
Near Infrared ◽  
Strong Field ◽  
Imaging Technique ◽  
Near Field ◽  
Velocity Map Imaging ◽  
Single Shot ◽  
Surface Molecules ◽  
Nanoparticle Interactions ◽  
Field Response ◽  
Ion Species

Abstract Using single-shot velocity map imaging technique, explosion imaging of different ion species ejected from 50 nm SiO2 nanoparticles are obtained excitedly by strong near-infrared and ultraviolet femtosecond laser fields. Characteristic momentum distributions showing forward emission of the ions at low excitation intensities and shock wave behaviors at high intensities are observed. When the excitation intensity is close to the dissociative ionization threshold of the surface molecules, the resulting ion products can be used to image the instant near-field distributions. The underlying dynamics of shock formation are simulated by using a Coulomb explosion model. Our results allow one to distinguish the ultrafast strong-field response of various molecular species in nanosystems and will open a new way for further exploration of the underlying dynamics of laser-and-nanoparticle interactions.

scholarly journals Recent Advancements and Remaining Challenges Associated With Inner Magnetosphere Cross‐Energy/Population Interactions (IMCEPI)

2019 ◽  
Vol 124 (2) ◽  
pp. 886-897 ◽  
Author(s):  
Yiqun Yu ◽  
Mike W. Liemohn ◽  
Vania K. Jordanova ◽  
Colby Lemon ◽  
Jichun Zhang
Keyword(s):  
Inner Magnetosphere ◽  
Population Interactions
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