Electron energy deposition in atomic oxygen

Slinker, S. P.; Taylor, Ronald D.; Ali, A. W.

doi:10.1063/1.340491

Cited by 40 publications

(12 citation statements)

References 46 publications

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“…The simulation should include the magnetic mirror force, charge exchange, and energy loss due to collisions (Green & Stolaski, 1976; Slinker et al, 1988), with considering of the pitch angle scattering of precipitating electrons in the upper atmosphere (e.g., Prasad et al, 1985), and the effects of secondary electrons produced by precipitating electrons (e.g., Varney et al, 2014). As an observational study, however, a more realistic simulation is beyond the scope of the present paper and will be focused in a later paper.…”

Section: Discussionmentioning

confidence: 99%

The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field

Förster

Rong

et al. 2020

JGR Space Physics

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When the geomagnetic field is weak, the small mirror force allows precipitating charged particles to deposit energy in the ionosphere. This leads to an increase in ionospheric outflow from the Earth's polar cap region, but such an effect has not been previously observed because the energies of the ions of the polar ionospheric outflow are too low, making it difficult to detect the low-energy ions with a positively charged spacecraft. In this study, we found an anticorrelation between ionospheric outflow and the strength of the Earth's magnetic field. Our results suggest that the electron precipitation through the polar rain can be a main energy source of the polar wind during periods of high levels of solar activity. The decreased magnetic field due to spatial inhomogeneity of the Earth's magnetic field and its effect on outflow can be used to study the outflow in history when the magnetic field was at similar levels.Plain Language Summary Earth, Venus, and Mars have very different atmospheres although they are thought to possess similar atmospheres about 4.5 billion years ago. One of the main reasons considered for the losses of H 2 O and O 2 is dramatic decreases in the dipole magnetic field on Venus and Mars. Although the Earth has kept its intrinsic magnetic field, there are variations in both orientation and strength. Previous observations have confirmed that atmospheric loss is controlled by the orientation of the geomagnetic dipole. However, the effect of variations in the strength of the Earth's magnetic field on atmospheric outflow has not been addressed. In this study, we have focused on the polar wind, the dominant ionospheric outflow from the polar regions. Our results reveal an anticorrelation between the outflow and the strength of the Earth's magnetic field, offering us a clue on the ionospheric and atmospheric evolution with a changing magnetic field.

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Section: Discussionmentioning

confidence: 99%

The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field

Förster

Rong

et al. 2020

JGR Space Physics

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“…At present, WARP uses a very simple model to estimate impact-ionization cross sections [9], although the user may specify alternate values. In all the work here, we use a cross section of 5x10 -20 m 2 for ionization of H 2 by 300 keV K + .…”

Section: Methodsmentioning

confidence: 99%

Simulating electron clouds in high-current ion accelerators with solenoid focusing

Sharp

Grote

Cohen

et al. 2007

Nuclear Instruments and Methods in Physics Research Section A:

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Contamination from electrons is a concern for the solenoid-focused ion accelerators being developed for experiments in highenergy-density physics (HEDP). These electrons are produced directly by beam ions hitting lattice elements and intercepting disgnostics, or indirectly by ionization of desorbed neutral gas, and they are believed responsible for time dependence of the beam radius, emittance, and focal distance seen on the Solenoid Transport Experiment (STX) at Lawrence Berkeley National Laboratory. The electrostatic particle-in-cell code WARP has been upgraded to included the physics needed to simulate electron-cloud phenomena. We present preliminary self-consistent simulations of STX experiments suggesting that the observed time dependence of the beam stems from a complicated interaction of beam ions, desorbed neutrals, and electrons.

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“…Pioneering studies included Bretagne et al (1981) and Strickland and Ali (1982). Slinker et al (1988Slinker et al ( , 1990) solved a kinetic transport equation to describe the discrete entry of high energy electrons in atomic oxygen O and nitrogen N 2 and found W to be 27.9 eV and 38.8 eV at 1 keV. Sergienko and Ivanov (1993) computed the energy per ion pair in a multi-constituent Earth atmosphere for auroral electrons with a Monte Carlo code.…”

Section: Previous Studiesmentioning

confidence: 99%

Comprehensive calculation of the energy per ion pair or <I>W</I> values for five major planetary upper atmospheres

et al. 2011

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Abstract. The mean energy W expended in a collision of electrons with atmospheric gases is a useful parameter for fast aeronomy computations. Computing this parameter in transport kinetic models with experimental values can tell us more about the number of processes that have to be taken into account and the uncertainties of the models. We present here computations for several atmospheric gases of planetological interest (CO 2 , CO, N 2 , O 2 , O, CH 4 , H, He) using a family of multi-stream kinetic transport codes. Results for complete atmospheres for Venus, Earth, Mars, Jupiter and Titan are also shown for the first time. A simple method is derived to calculate W of gas mixtures from single-component gases and is conclusively checked against the W values of these planetary atmospheres. Discrepancies between experimental and theoretical values show where improvements can be made in the measurement of excitation and dissociation cross-sections of specific neutral species, such as CO 2 and CO.

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Electron energy deposition in atomic oxygen

Cited by 40 publications

References 46 publications

The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field

The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field

Simulating electron clouds in high-current ion accelerators with solenoid focusing

Comprehensive calculation of the energy per ion pair or <I>W</I> values for five major planetary upper atmospheres

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Electron energy deposition in atomic oxygen

Cited by 40 publications

References 46 publications

The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field

The Polar Wind Modulated by the Spatial Inhomogeneity of the Strength of the Earth's Magnetic Field

Simulating electron clouds in high-current ion accelerators with solenoid focusing

Comprehensive calculation of the energy per ion pair or &lt;I&gt;W&lt;/I&gt; values for five major planetary upper atmospheres

Contact Info

Product

Resources

About

Comprehensive calculation of the energy per ion pair or <I>W</I> values for five major planetary upper atmospheres