Reduction of the Coherent Betatron Oscillation Amplitude by an RF Electric Field for the Fermilab Muon $g − 2$ Experiment

The numerical results of a set of nonlinear equations for a modulation-doped GaAs/AlGaAs heterostructure under external fields are presented. For pure dc bias at a fixed magnetic field, we observe the self-sustained oscillations due to the traveling high electric field domain in the system. Varying the magnetic field, the width of the domain and the oscillation amplitude will be changed. By imposing the microwave irradiation, the system shows frequency locking, quasiperiodicity, and chaos depending on the amplitude and the frequency of the microwave. It is shown that these interesting oscillations are connected with the high electric field domains.

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Acceleration of coagulation of particles in oil utilizing an a.c. electric field

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/095440604322900444 ◽

2004 ◽

Vol 218 (3) ◽

pp. 317-326 ◽

Cited By ~ 1

Author(s):

H Yanada ◽

N Nishimura ◽

T Imagawa

Keyword(s):

Electric Field ◽

Double Layer ◽

High Performance ◽

Oscillation Amplitude ◽

Small Diameter ◽

Silica Particles ◽

Insulating Liquids ◽

Coagulation Of Particles ◽

Electrostatic Filter ◽

Spherical Silica Particles

This paper describes an experimental investigation of the coagulation of particles in oil accelerated by the action of an a.c. electric field. The ultimate goal of the investigation is to develop a high-performance electrostatic filter for insulating liquids. In order to reveal the coagulation mechanism and find out the mechanical conditions suitable for the coagulation, the effects of various factors on the coagulation are investigated using spherical silica particles of 2, 4 and 6 μm in diameter. The coagulating state of the silica particles in oil is observed using a video-microscope with a CCD (charge coupled device) camera under various conditions. It is shown that the coagulation is better promoted with larger particles and that the particles having a small diameter are not easily coagulated. It is also shown that the oscillation amplitude relative to the double-layer thickness dominates the coagulation phenomenon. The experimental results suggest that when the surface charge on a particle and the charge in the surrounding double layer are appropriately polarized by the influence of the a.c. electric field, the coagulation is accelerated by virtue of a (relatively) strong attractive force acting between two-particle-double-layer pairs.

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The effect of limiter biasing on the plasma edge rotation and MHD activities

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194514603329 ◽

2014 ◽

Vol 32 ◽

pp. 1460332

Author(s):

A. Lahazi ◽

P. Khorshid ◽

M. Ghoranneviss

Keyword(s):

Electric Field ◽

Oscillation Amplitude ◽

Sharp Decrease ◽

Rotation Frequency ◽

Radial Electric Field ◽

Dominant Mode ◽

Floating Potential ◽

Plasma Edge ◽

Magnetic Island ◽

Toroidal Rotation

Plasma edge rotations and magnetohydrodynamic behaviors have been studied during radial electric field variations in IR-T1 tokamak. An external positive limiter bias has been used as an external radial electric field. The profiles of radial electric field, floating potential, poloidal and toroidal rotation velocities and MHD activities have been studied during positive limiter bias. The poloidal and toroidal velocities reduced when the bias was applied and their fluctuations on the plasma edge became smoother furthermore. A significant excitation in dominant mode (4, 1) oscillation amplitude and a sharp decrease in magnetic island rotation frequency have been seen.

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Resolution in photoelectron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086593 ◽

1991 ◽

Vol 49 ◽

pp. 458-459

Author(s):

G. F. Rempfer

Keyword(s):

Electron Microscopy ◽

Electric Field ◽

Ultraviolet Light ◽

Uniform Field ◽

Virtual Image ◽

Lens System ◽

Photoemission Electron Microscopy ◽

Planar Electrode ◽

Electron Lens ◽

Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

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Field-assisted ionization theory for microscopists

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171833 ◽

1994 ◽

Vol 52 ◽

pp. 820-821

Author(s):

Patrick P. Camus

Keyword(s):

Electric Field ◽

Electron Tunneling ◽

Ionization Probability ◽

Critical Distance ◽

Tunneling Probability ◽

Field Ionization ◽

Radius Of Curvature ◽

Field Evaporation ◽

A Value ◽

Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

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