Electric field emission of electrons from negatively charged spherical particles in a dusty plasma in the regime of nonlinear screening

2010 ◽  
Vol 88 (8) ◽  
pp. 617-621 ◽  
Author(s):  
Gyan Prakash
Keyword(s):  
Potential Energy ◽  
Electric Field ◽  
Dusty Plasma ◽  
Field Emission ◽  
Energy Barrier ◽  
Tunneling Probability ◽  
Spherical Particles ◽  
Potential Energy Barrier ◽  
The Matrix ◽  
Field Emission Of Electrons

This note presents a discussion of the electric field emission from negatively charged spherical particles in a dusty plasma in the regime of nonlinear screening. Using the appropriate representation of the nonlinear screening by Gurevich and the matrix method, the tunneling probability of an electron through the potential energy barrier around the particle has been evaluated as a function of its radial energy; corresponding values of the current density have also been obtained. A discussion of numerical results, thus obtained concludes the presentation.

Field Emission Basics: The Water Bucket Analogy

1995 ◽  
Vol 3 (10) ◽  
pp. 20-21
Author(s):  
Doug Rathkey
Keyword(s):  
Kinetic Energy ◽  
Energy Level ◽  
Potential Energy ◽  
Electric Field ◽  
Cathode Material ◽  
Fermi Level ◽  
Field Emission ◽  
Energy Barrier ◽  
Thermionic Emission ◽  
Potential Energy Barrier

In the water bucket analogy (Figure 1), the water level in a bucket represents the Fermi level - the highest occupied energy level in the cathode material. The work function is the energy required to get the “water droplets” (electrons) from the top of the liquid out of the bucket and ever the side (i.e., the distance equivalent to the potential energy barrier).In photoemission, the energy of a photon can remove an electron at the Fermi level from the cathode material and can impart enough kinetic energy of travel to allow it to escape from the bucket (Figure 1a). In thermionic emission, heat provides the energy to boil the electrons off and out of the bucket (Figure 1b). Finally, in field emission, a high electric field can thin the side of the bucket enough so that the electrons can tunnel right through it (Figure 1c). There are two types of field emission: cold field emission (CFE) and Schottky emission (SE).

Effect of electric field emission on charging of dust particles in a plasma

2009 ◽  
Vol 76 (2) ◽  
pp. 159-168 ◽  
Author(s):  
MAHENDRA SINGH SODHA ◽  
AMRIT DIXIT ◽  
GYAN PRAKASH
Keyword(s):  
Electric Field ◽  
Field Emission ◽  
Spherical Particles ◽  
Dust Particles ◽  
Density Of Electrons ◽  
Field Emission Of Electrons

AbstractThe authors have considered the charging of spherical particles in a plasma, taking into account the electric field emission of electrons from the dust particles and the change in the electron/ion densities in the plasma. The dependence of the charge of a particle and electron/ion densities on the radius and number of dust particles and the density of electrons/ions and the temperature in the undisturbed plasma has been studied numerically without and with the inclusion of the electric field emission of electrons from the particles. It is seen that both the electric field emission and the electron/ion kinetics significantly affect the charging process.

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.

Hybrid-Bistable Vibration Energy Harvester With Adaptive Potential Well

2018 ◽  
Author(s):  
Jinki Kim ◽  
Patrick Dorin ◽  
K. W. Wang
Keyword(s):  
Energy Harvesting ◽  
Potential Energy ◽  
Cantilever Beam ◽  
Potential Barrier ◽  
Energy Barrier ◽  
Electrical Power ◽  
Vibration Energy ◽  
Frequency Spectra ◽  
Potential Energy Barrier ◽  
Piezoelectric Energy

Many common environmental vibration sources exhibit low and broad frequency spectra. In order to exploit such excitations, energy harvesting architectures utilizing nonlinearity, especially bistability, have been widely studied since the energetic interwell oscillations between their stable equilibria can provide enhanced power harvesting capability over a wider bandwidth compared to the linear counterpart. However, one of the limitations of these nonlinear architectures is that the interwell oscillation regime may not be activated for a low excitation level that is not strong enough to overcome the potential energy barrier, thus resulting in low amplitude intrawell response which provides poor energy harvesting performance. While the strategic integration of bistability and additional dynamic elements has shown potential to improve broadband energy harvesting performance by lowering the potential barrier, there is a clear opportunity to further improve the energy harvesting performance by extracting electrical power from the kinetic energy in the additional element that is induced when the potential barrier is lowered. To explore this opportunity and advance the state of the art, this research develops a novel hybrid bistable vibration energy harvesting system with a passive mechanism that not only adaptively lowers the potential energy barrier level to improve broadband performance but also exploits additional means to capture more usable electrical power. The proposed harvester is comprised of a cantilever beam with repulsive magnets, one attached at the free end and the other attached to a linear spring that is axially aligned with the cantilever (a spring-loaded magnet oscillator). This new approach capitalizes on the adaptive bistable potential that is passively realized by the spring-loaded magnet oscillator, which lowers the double-well potential energy barrier thereby facilitating the interwell oscillations of the cantilever across a broad range of excitation conditions, especially for low excitation amplitudes and frequencies. The interwell oscillation of the cantilever beam enhances not only the piezoelectric energy harvesting from the beam but also the electromagnetic energy harvesting from the spring-loaded magnet oscillator by inducing large amplitude vibrations of the magnet oscillator. Numerical investigations found that the proposed architecture yields significantly enhanced energy harvesting performance compared to the conventional bistable harvester with fixed magnet.

scholarly journals The enzyme aromatic amine dehydrogenase induces a substrate conformation crucial for promoting vibration that significantly reduces the effective potential energy barrier to proton transfer

2008 ◽  
Vol 5 (suppl_3) ◽  
pp. 225-232 ◽  
Author(s):  
Linus O Johannissen ◽  
Nigel S Scrutton ◽  
Michael J Sutcliffe
Keyword(s):  
Potential Energy ◽  
Proton Transfer ◽  
Aromatic Amine ◽  
Effective Potential ◽  
Energy Barrier ◽  
Transfer Event ◽  
Effective Potential Energy ◽  
Potential Energy Barrier ◽  
Mechanical Methods ◽  
Amine Dehydrogenase

The role of promoting vibrations in enzymic reactions involving hydrogen tunnelling is contentious. While models incorporating such promoting vibrations have successfully reproduced and explained experimental observations, it has also been argued that such vibrations are not part of the catalytic effect. In this study, we have employed combined quantum mechanical/molecular mechanical methods with molecular dynamics and potential energy surface calculations to investigate how enzyme and substrate motion affects the energy barrier to proton transfer for the rate-limiting H-transfer step in aromatic amine dehydrogenase (AADH) with tryptamine as substrate. In particular, the conformation of the iminoquinone adduct induced by AADH was found to be essential for a promoting vibration identified previously—this lowers significantly the ‘effective’ potential energy barrier, that is the barrier which remains to be surmounted following collective, thermally equilibrated motion attaining a quantum degenerate state of reactants and products. When the substrate adopts a conformation similar to that in the free iminoquinone, this barrier was found to increase markedly. This is consistent with AADH facilitating the H-transfer event by holding the substrate in a conformation that induces a promoting vibration.

scholarly journals The effect of dissipation on the torque and force experienced by nanoparticles in an AC field

2014 ◽  
Vol 29 (01) ◽  
pp. 1450240
Author(s):  
F. Claro ◽  
R. Fuchs ◽  
P. Robles ◽  
R. Rojas
Keyword(s):  
Potential Energy ◽  
Electric Field ◽  
Interaction Potential ◽  
Interparticle Distance ◽  
Spherical Particles ◽  
Particle Rotation ◽  
The Past ◽  
Ac Electric Field ◽  
Ac Field ◽  
Interaction Potential Energy

We discuss the force and torque acting on spherical particles in an ensemble in the presence of a uniform AC electric field. We show that for a torque causing particle rotation to appear the particle must be absorptive. Our proof includes all electromagnetic excitations, which in the case of two or more particles gives rise to one or more resonances in the spectrum of force and torque depending on interparticle distance. Several peaks are found in the force and torque between two spheres at small interparticle distances, which coalesce to just one as the separation grows beyond three particle radii. We also show that in the presence of dissipation the force on each particle is nonconservative and may not be derived from the classical interaction potential energy as has been done in the past.

The potential energy barrier of the state in KLi

2009 ◽  
Vol 73 (1) ◽  
pp. 117-120 ◽  
Author(s):  
W. Jastrzebski ◽  
P. Kowalczyk ◽  
A. Pashov ◽  
J. Szczepkowski
Keyword(s):  
Potential Energy ◽  
Energy Barrier ◽  
The State ◽  
Potential Energy Barrier
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