Io's auroral emissions via global hybrid plasma simulations

Abstract. We tackle the Io's aurora source and topology by carrying out a set of global hybrid simulations of Io's interaction with the plasma torus under different model geometry and background conditions. Based on the simulated results, we compute the photon emission rates above the Io's surface and present the resulting images from a virtual telescope and topological maps showing the distribution of the emission sources across the moon's surface. This allows us to compare the structure of the aurora with the real observations and conclude on the different assumptions. We found a reasonable agreement with the real observations in the case of non-collisional background electron populations. From the comparison of the local magnetic field topology with model aurora structures, we also infer that an induced dipole feature is more probable to play a role in the interaction of Io with the Jovian magnetosphere. In addition we also examine the potential contribution of energetic electron beams, being observed in the Io's wake region, to the overall auroral emissions.

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Symmetry-tailored patterns and polarizations of single-photon emission

Nanophotonics ◽

10.1515/nanoph-2020-0208 ◽

2020 ◽

Vol 9 (11) ◽

pp. 3557-3565

Author(s):

Guorui Zhang ◽

Ying Gu ◽

Qihuang Gong ◽

Jianjun Chen

Keyword(s):

Single Photon ◽

Photon Emission ◽

Silver Nanowire ◽

Emission Rates ◽

Single Photon Emission ◽

Emission Pattern ◽

Single Photon Emitters ◽

Resonant Modes ◽

Oriented Dipole ◽

Centrally Symmetric

AbstractDue to small optical mode volumes and linear polarizations of surface-plasmon-polariton (SPP) resonant modes in metallic antennas, it is very difficult to obtain complex emission patterns and polarizations for single-photon emitters. Herein, nonresonant enhancement in a silver nanowire is used to both enhance emission rates and extract a z-oriented dipole, and then the symmetry of metallic nanostructures is proposed to tailor the patterns and polarizations of single-photon emission. The emission pattern of a quantum dot located close to a metallic nanostructure with a symmetric axis is split into multiple flaps. The number of splitting flaps is equal to the order of the symmetric axis. Moreover, the electric vectors of the emitted photons become centrally symmetric about the symmetric axis. The above phenomena are well explained by both a simulation and an image dipole model. The structural-symmetry-tailoring mechanism may open up a new avenue in the design of multifunctional and novel quantum-plasmonic devices.

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The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2

Annales Geophysicae ◽

10.5194/angeo-19-593-2001 ◽

2001 ◽

Vol 19 (6) ◽

pp. 593-600 ◽

Cited By ~ 7

Author(s):

O. Norberg ◽

J. D. Winningham ◽

H. Lauche ◽

W. Keith ◽

W. Puccio ◽

...

Keyword(s):

Technological Development ◽

Low Cost ◽

Local Magnetic Field ◽

High Temporal Resolution ◽

Two Dimensional ◽

Spin Plane ◽

Low Mass ◽

Instruments And Techniques ◽

Auroral Emissions ◽

Auroral Phenomena

Abstract. The miniature electron and ion spectrometer MEDUSA on Astrid-2 consists of two "top-hat"-type spherical electrostatic analyzers, sharing a common top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second) allow for very high temporal resolution measurements of a two-dimensional slice of the particle distribution function. The energy range covered, is in the case of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA is mounted with its aperture close to the spin plane of Astrid-2, which allows for good pitch-angle coverage when the local magnetic field is in the satellite spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral emissions. Using the spacecraft spin and orbital motion, it is possible to create two-dimensional images from the data. Spin-scanning photometers, such as PIA, are low-cost, low mass alternatives to auroral imagers, but place constraints on the satellite attitude. Data from MEDUSA are used to study processes in the auroral region, in particular, electrodynamics of aurora and "black aurora". MEDUSA is also a technological development, paving the way for highly capable, miniaturized particle spectrometers.Key words. Ionosphere (instruments and techniques) – Magnetospheric physics (auroral phenomena; instruments and techniques)

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Spontaneous hot-carrier photon emission rates in silicon: Improved modeling and applications to metal oxide semiconductor devices

Physical Review B ◽

10.1103/physrevb.65.195209 ◽

2002 ◽

Vol 65 (19) ◽

Cited By ~ 9

Author(s):

M. Pavesi ◽

P. L. Rigolli ◽

M. Manfredi ◽

P. Palestri ◽

L. Selmi

Keyword(s):

Metal Oxide ◽

Semiconductor Devices ◽

Photon Emission ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor ◽

Emission Rates ◽

Hot Carrier

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Modeling and compensating dynamic nonlinearities in LED photon-emission rates to enhance OWC

Light-Emitting Devices, Materials, and Applications ◽

10.1117/12.2511099 ◽

2019 ◽

Cited By ~ 2

Author(s):

Shokoufeh Mardani ◽

Anton Alexeev ◽

Jean-Paul Linnartz

Keyword(s):

Photon Emission ◽

Emission Rates

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Dilepton and photon emission rates from a hadronic gas. III

Physical Review C ◽

10.1103/physrevc.58.2899 ◽

1998 ◽

Vol 58 (5) ◽

pp. 2899-2906 ◽

Cited By ~ 14

Author(s):

C.-H. Lee ◽

H. Yamagishi ◽

I. Zahed

Keyword(s):

Photon Emission ◽

Emission Rates

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Statistical patterns in X-ray and UV auroral emissions and energetic electron precipitation

Journal of Geophysical Research Atmospheres ◽

10.1029/2000ja003041 ◽

2001 ◽

Vol 106 (A4) ◽

pp. 5907-5911 ◽

Cited By ~ 6

Author(s):

P. C. Anderson ◽

S. M. Petrinec ◽

K. Liou

Keyword(s):

Energetic Electron ◽

Electron Precipitation ◽

X Ray ◽

Auroral Emissions

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Modelling of N21P emission rates in aurora using various cross sections for excitation

Annales Geophysicae ◽

10.5194/angeo-27-2545-2009 ◽

2009 ◽

Vol 27 (6) ◽

pp. 2545-2553 ◽

Cited By ~ 8

Author(s):

M. Ashrafi ◽

B. S. Lanchester ◽

D. Lummerzheim ◽

N. Ivchenko ◽

O. Jokiaho

Keyword(s):

Cross Sections ◽

Radar Data ◽

Optical Measurements ◽

Emission Rates ◽

Incoherent Scatter ◽

Temporal And Spatial ◽

The Cross ◽

Auroral Emissions ◽

Auroral Imager ◽

Magnetic Zenith

Abstract. Measurements of N21P auroral emissions from the (4,1) and (5,2) bands have been made at high temporal and spatial resolution in the region of the magnetic zenith. The instrument used was the auroral imager ASK, situated at Ramfjordmoen, Norway (69.6 N, 19.2 E) on 22 October 2006. Measurements from the European Incoherent Scatter Radar (EISCAT) have been combined with the optical measurements, and incorporated into an ionospheric model to obtain height profiles of electron density and emission rates of the N21P bands. The radar data provide essential verification that the energy flux used in the model is correct. One of the most important inputs to the model is the cross section for excitation to the B3Πg electronic state, as well as the cross sections to higher states from which cascading into the B state occurs. The balance equations for production and loss of the populations of all levels in each state are solved in order to find the cascade contributions. Several sets of cross sections have been considered, and selected cross sections have been used to construct "emission" cross sections for the observed bands. The resulting brightnesses are compared with those measured by ASK. The importance of specific contributions from cascading is found, with more than 50% of the total brightness resulting from cascading. The cross sections used are found to produce a range of brightnesses well within the uncertainty of both the modelled and measured values.

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A preliminary study of Magnetosphere-Ionosphere-Thermosphere coupling key parameters at Jupiter Based on Juno multi-instrument data and modelling tools

10.5194/epsc2020-979 ◽

2020 ◽

Author(s):

Michel Blanc ◽

Yuxian Wang ◽

Nicolas Andre ◽

Pierre-Louis Blelly ◽

Corentin Louis ◽

...

Keyword(s):

Electric Fields ◽

Plasma Source ◽

Neutral Atmosphere ◽

Solar Wind Interaction ◽

Jovian Magnetosphere ◽

Use Of Data ◽

Field Lines ◽

Auroral Emissions ◽

Coupling Processes

The dynamics of the Jovian magnetosphere is controlled by the complex interplay of the planet&#8217;s fast rotation, its solar-wind interaction and its main plasma source at the Io torus. Juno observations have amply demonstrated that the Magnetosphere-Ionosphere-Thermosphere (MIT) coupling processes and regimes which control this interplay are significantly different from their Earth and Saturn counterparts. At the ionospheric level, these MIT coupling processes can be characterized by a set of key parameters which include ionospheric electrodynamic parameters (conductances, currents and electric fields), exchanges of particles along field lines and auroral emissions. Knowledge of these key parameters in turn makes it possible to estimate the net deposition/extraction of momentum and energy into/out of the Jovian upper atmosphere. We will present a method combining Juno multi-instrument data (MAG, JADE, JEDI, UVS, JIRAM and WAVES), adequate modelling tools (the TRANSPLANET ionospheric dynamics model and a simplified set of ionospheric current closure equations) and the AMDA data handling tools to provide preliminary estimates of these key parameters and their variation along the ionospheric footprint of Juno&#8217;s magnetic field line and across the auroral ovals for three of the first perijoves of the mission. We will discuss how this synergistic use of data and models can also contribute to provide a better determination of poorly known parameters such as the vertical structure of the auroral and polar Jovian neutral atmosphere. &#160;

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