scholarly journals Electron acceleration in underdense plasmas described with a classical effective theory

2015 ◽  
Vol 33 (2) ◽  
pp. 307-313 ◽  
Author(s):  
M. A. Pocsai ◽  
S. Varró ◽  
I. F. Barna
Keyword(s):  
Experimental Data ◽  
Continuous Medium ◽  
Equations Of Motion ◽  
Electron Acceleration ◽  
Index Of Refraction ◽  
Effective Theory ◽  
Electron Motion ◽  
Particle In Cell ◽  
Underdense Plasmas ◽  
Relativistic Equations

AbstractAn effective theory of laser–plasma-based particle acceleration is presented. Here we treated the plasma as a continuous medium with an index of refraction nm in which a single electron propagates. Because of the simplicity of this model, we did not perform particle-in-cell (PIC) simulations in order to study the properties of the electron acceleration. We studied the properties of the electron motion due to the Lorentz force and the relativistic equations of motion were numerically solved and analyzed. We compared our results with PIC simulations and experimental data.

PONDEROMOTIVE SCATTERING AT RELATIVISTIC LASER INTENSITIES

1995 ◽  
Vol 04 (04) ◽  
pp. 799-815 ◽  
Author(s):  
S. P. GORESLAVSKY ◽  
N. B. NAROZHNY
Keyword(s):  
Electromagnetic Wave ◽  
Laser Pulse ◽  
Exact Solutions ◽  
Plane Electromagnetic Wave ◽  
Equations Of Motion ◽  
Relativistic Velocity ◽  
Electron Motion ◽  
Average Electron ◽  
Relativistic Equations

We present a summary on the exact solutions to the classical relativistic equations of motion in the field of a plane electromagnetic wave and describe a modification of the averaging procedure, which yields equations governing the average electron motion in the field of a focused laser pulse when an electron oscillates at relativistic velocity. Applications to the barrier suppression ionization and Thompson radiation are briefly discussed.

A Model for Otolith Dynamic Response with a Viscoelastic Gel Layer

1991 ◽  
Vol 1 (2) ◽  
pp. 139-151
Author(s):  
J.W. Grant ◽  
J.R. Cotton
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Equations Of Motion ◽  
Otolith Organs ◽  
Major Contributor ◽  
Viscoelastic Solid ◽  
Gel Layer ◽  
Element System ◽  
Experimental Data Analysis ◽  
Finite Difference Techniques

The otolith organs were modeled mathematically as a 3-element system consisting of a viscous endolymph fluid in contact with a rigid otoconial layer that is attached to the skull by a gel layer. The gel layer was considered to be a viscoelastic solid, and was modeled as a simple Kelvin material. The governing differential equations of motion were derived and nondimensionalized, yielding 3 nondimensional parameters: nondimensional density, nondimensional viscosity, and nondimensional elasticity. The equations were solved using finite difference techniques on a digital computer. By comparing the model’s response with previous experimental research, values for the nondimensional parameters were found. The results indicate that the inclusion of viscous and elastic effects in the gel layer are necessary for the model to produce otoconial layer deflections that are consistent with physiologic displacements. Future experimental data analysis and mathematical modeling effects should include viscoelastic gel layer effects, as this is a major contributor to system damping and response.

BALLISTIC ELECTRON ACCELERATION NEGATIVE-DIFFERENTIAL-CONDUCTIVITY DEVICES

2007 ◽  
Vol 17 (01) ◽  
pp. 173-176 ◽  
Author(s):  
BARBAROS ASLAN ◽  
LESTER F. EASTMAN ◽  
WILLIAM J. SCHAFF ◽  
XIAODONG CHEN ◽  
MICHAEL G. SPENCER ◽  
...  
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Electron Acceleration ◽  
Negative Differential Conductivity ◽  
Differential Conductivity ◽  
Experimental Development ◽  
Ballistic Electron

We present the experimental development and characterization of GaN ballistic diodes for THz operation. Fabricated devices have been described and gathered experimental data is discussed. The major problem addressed is the domination of the parasitic resistances which significantly reduce the accelerating electric field across the ballistic region (intrinsic layer).

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.

Modeling of Multibody Flexible Articulated Structures With Mutually Coupled Motions: Part II — Application and Results

1992 ◽  
Author(s):  
Jiechi Xu ◽  
Joseph R. Baumgarten
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Open Loop ◽  
Body Motion ◽  
Universal Joint ◽  
Open Loop System ◽  
Numerical Examples ◽  
Kinematic Properties ◽  
Good Agreement

Abstract The application of the systematic procedures in the derivation of the equations of motion proposed in Part I of this work is demonstrated and implemented in detail. The equations of motion for each subsystem are derived individually and are assembled under the concept of compatibility between the local kinematic properties of the elastic degrees of freedom of those connected elastic members. The specific structure under consideration is characterized as an open loop system with spherical unconstrained chains being capable of rotating about a Hooke’s or universal joint. The rigid body motion, due to two unknown rotations, and the elastic degrees of freedom are mutually coupled and influence each other. The traditional motion superposition approach is no longer applicable herein. Numerical examples for several cases are presented. These simulations are compared with the experimental data and good agreement is indicated.

General Equations of a Helical Spring With a Cup Damper and Static Verification

1997 ◽  
Vol 119 (2) ◽  
pp. 319-326 ◽  
Author(s):  
Ming Hsun Wu ◽  
Jing Yuan Ho ◽  
Wensyang Hsu
Keyword(s):  
Experimental Data ◽  
Pitch Angle ◽  
Equations Of Motion ◽  
Maximum Error ◽  
Dynamic Equations ◽  
Helical Spring ◽  
Static Force ◽  
Static Verification ◽  
Simulation Results ◽  
Force Displacement

In this study, we derive the general equations of motion for the helical spring with a cup damper by considering the damper’s dilation and varying pitch angle of the helical spring. These dynamic equations are simplified to correlate with previous models. The static force-displacement relation is also derived. The extra stiffness due to the damper’s dilation considered in the force-displacement relation is the first such modeling in this area. In addition, a method is presented to predict the compressing spring’s coil close length and is then verified by experimental data. Moreover, the simulation results of the static force-displacement relation are found to correspond to the experimental data. The maximum error is around 0.6 percent.

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