scholarly journals On the Electrical Effects of the Presence of Fluff on the Surface of Cosmic Dust Grains

1985 ◽  
Vol 85 ◽  
pp. 341-346
Author(s):  
J.P. Lafon ◽  
J.M. Millet
Keyword(s):  
Electric Field ◽  
Field Emission ◽  
Analytical Model ◽  
Spherical Body ◽  
Cosmic Dust ◽  
Dust Grains ◽  
Astrophysical Plasma

AbstractWe give a n analytical model describing the effects of “fluff” on the potential and the electric field on and close to a charged spherical body embedded in an astrophysical plasma. The consequences are investigated for dust grains biased at positive or negative potentials but large enough for electron or ion field emission to be active.

scholarly journals Optically Induced Field-Emission Source Based on Aligned Vertical Carbon Nanotube Arrays

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1810
Author(s):  
Mengjie Li ◽  
Qilong Wang ◽  
Ji Xu ◽  
Jian Zhang ◽  
Zhiyang Qi ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Electric Field ◽  
Field Emission ◽  
Field Enhancement ◽  
Absorption Efficiency ◽  
Photon Absorption ◽  
Nanotube Arrays ◽  
Carbon Nanotube Arrays ◽  
Induced Field ◽  
Optically Induced

Due to the high field enhancement factor and photon-absorption efficiency, carbon nanotubes (CNTs) have been widely used in optically induced field-emission as a cathode. Here, we report vertical carbon nanotube arrays (VCNTAs) that performed as high-density electron sources. A combination of high applied electric field and laser illumination made it possible to modulate the emission with laser pulses. When the bias electric field and laser power density increased, the emission process is sensitive to a power law of the laser intensity, which supports the emission mechanism of optically induced field emission followed by over-the-barrier emission. Furthermore, we determine a polarization dependence that exhibits a cosine behavior, which verifies the high possibility of optically induced field emission.

An analytical model for the lateral channel electric field in LDD structures

1990 ◽  
Vol 37 (10) ◽  
pp. 2254-2264 ◽  
Author(s):  
Y. Hu ◽  
R.V.H. Booth ◽  
M.H. White
Keyword(s):  
Electric Field ◽  
Analytical Model ◽  
Lateral Channel

Compositional in situ analysis of dusty material stemming from Saturn’s main rings

2021 ◽  
Author(s):  
Simon Linti ◽  
Jon Hillier ◽  
Christian Fischer ◽  
Hsiang-Wen Hsu ◽  
Mario Trieloff ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Impact Ionization ◽  
Source Region ◽  
Relative Sensitivity ◽  
Cosmic Dust ◽  
Dust Grains ◽  
Element Ratios ◽  
Sensitivity Factors ◽  
Compositional Diversity

<p>During the final mission phase, the Cassini spacecraft travelled through the gap between Saturn and its innermost D ring. One goal of these highly inclined orbits was sampling the dust population, mostly made of impact ejecta from the main rings, in the vicinity of the planet. These in situ measurements were primarily carried out by the Cosmic Dust Analyzer (CDA) onboard the spacecraft, which provided time-of-flight mass spectra of individual ice and dust grains, mostly between about 10 and 50 nm in size. Here we present an update on the composition of the silicate dust fraction stemming from Saturn’s main rings, which makes up about 30 % of the observed particles with water ice being the remaining fraction [1].</p> <p>Elemental analysis of the silicate spectra was performed using an updated deconvolution method, based on a technique originally applied to the interpretation of CDA interstellar dust measurements [2]. Neighboring spectral peaks due to mineral-forming ions such as Mg<sup>+</sup>, Al<sup>+</sup> and Si<sup>+</sup> are often unresolvable, because of CDA’s relatively low (m/dm = 20–50) mass resolution [3]. Therefore, application of a deconvolution technique is required to disentangle the peak interferences and derive valuable compositional information. The robustness of the applied method has been tested and optimized through comparison with an independent automated fit algorithm. In order to calculate elemental abundances within the particles, the derived ion abundances were combined with experimentally-determined relative sensitivity factors (RSFs) [4]. To provide context to the measured element ratios, we compared them with a variety of space-relevant materials. We find an overlap with chondritic material for Mg/Si and Fe/Mg ratios. The observed range within the element ratios, however, indicates the contribution of a variety of minerals such as olivine, plagioclase or pyroxenes. Although our results agree with realistic mineral compositions, the calculated abundances of Al<sup>+</sup> ions are still relatively uncertain and can be seen as an upper limit.</p> <p>Additionally, we present the results of a dynamical model, which allow us to derive the likely source region within the main rings of individually detected silicate grains. We find the C and B rings to be the most likely sources of the vast majority of grains with the D ring being only a minor source. Currently an analysis of compositional diversity between the different ring segments is under way.</p> <p> </p> <p><strong>References</strong></p> <p>[1] H.-W. Hsu et al. (2018) In situ collection of dust grains falling from Saturn’s rings into its atmosphere. Science 362.</p> <p>[2] N. Altobelli et al. (2016) Flux and composition of interstellar dust at Saturn from Cassini’s Cosmic Dust Analyzer. Science 352, 312–318.</p> <p>[3] R. Srama et al. (2004) The Cassini Cosmic Dust Analyzer. Space Science Reviews 114, 465–518.</p> <p>[4] K. Fiege et al. (2014) Calibration of relative sensitivity factors for impact ionization detectors with high-velocity silicate microparticles. Icarus 241, 336–345.</p>

Nanotube Carbon Structure Tips - A Source of High Field Emission of Electrons

1994 ◽  
Vol 359 ◽  
Author(s):  
Leonid A. Chernozatonskii ◽  
Yu.V. Gulyaev ◽  
Z.Ja. Kosakoyskaja ◽  
N.I. Sinitsyn ◽  
G.V. Torgashov ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Emission ◽  
Quartz Glass ◽  
High Field ◽  
Emission Current ◽  
Carbon Structure ◽  
Glass Density ◽  
And Inversion ◽  
Field Emission Of Electrons

ABSTRACTWe present the finding of experiments of considerable field emission from the films consisting of nanotube carbon structureson various substrates (Si, quartz, glass): density of emission current was up to 1-3 A/cm2 while electric field was about 100 V/μ. The “reconstruction” and “inversion” of field emission have also been observed after current breakdown.

Ion acceleration by multiple laser pulses and their spontaneous electromagnetic fields in plasma

2008 ◽  
Vol 74 (1) ◽  
pp. 111-118
Author(s):  
FEN-CE CHEN
Keyword(s):  
Magnetic Fields ◽  
Electric Field ◽  
Analytical Model ◽  
Electromagnetic Fields ◽  
Equations Of Motion ◽  
Charged Particles ◽  
Laser Pulses ◽  
The Self ◽  
Electric And Magnetic Fields ◽  
Relativistic Equations

AbstractThe acceleration of ions by multiple laser pulses and their spontaneously generated electric and magnetic fields is investigated by using an analytical model for the latter. The relativistic equations of motion of test charged particles are solved numerically. It is found that the self-generated axial electric field plays an important role in the acceleration, and the energy of heavy test ions can reach several gigaelectronvolts.

Radial component of vortex electric field force

2021 ◽  
Vol 11 (1) ◽  
pp. 32-35
Author(s):  
Vasyl Tchaban ◽  
Keyword(s):  
Electric Field ◽  
Equations Of Motion ◽  
Spherical Body ◽  
Radial Component ◽  
Force Interaction ◽  
Finite Speed ◽  
The Third ◽  
Electric Field Force ◽  
Electrically Charged ◽  
Positively Charged

he differential equations of motion of electrically charged bodies in an uneven vortex electric field at all possible range of velocities are obtained in the article. In the force interaction, in addition to the two components – the Coulomb and Lorentz forces – the third component of a hitherto unknown force is involved. This component turned out to play a crucial role in the dynamics of movement. The equations are written in the usual 3D Euclidean space and physical time.This takes into account the finite speed of electric field propagation and the law of electric charge conservation. On this basis, the trajectory of the electron in an uneven electric field generated by a positively charged spherical body is simulated. The equations of motion are written in vector and coordinate forms. A physical interpretation of the obtained mathematical results is given. Examples of simulations are given.

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