scholarly journals Transverse electromagnetic Hermite–Gaussian mode-driven direct laser acceleration of electron under the influence of axial magnetic field

2018 ◽  
Vol 36 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Harjit Singh Ghotra ◽  
Dino Jaroszynski ◽  
Bernhard Ersfeld ◽  
Nareshpal Singh Saini ◽  
Samuel Yoffe ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Applied Magnetic Field ◽  
Axial Magnetic Field ◽  
Energy Gain ◽  
Electron Interaction ◽  
Direct Laser ◽  
Tem Mode ◽  
Laser Acceleration ◽  
Transverse Electromagnetic

AbstractHermite–Gaussian (HG) laser beam with transverse electromagnetic (TEM) mode indices (m, n) of distinct values (0, 1), (0, 2), (0, 3), and (0, 4) has been analyzed theoretically for direct laser acceleration (DLA) of electron under the influence of an externally applied axial magnetic field. The propagation characteristics of a TEM HG beam in vacuum control the dynamics of electron during laser–electron interaction. The applied magnetic field strengthens the $\vec v \times \vec B$ force component of the fields acting on electron for the occurrence of strong betatron resonance. An axially confined enhanced acceleration is observed due to axial magnetic field. The electron energy gain is sensitive not only to mode indices of TEM HG laser beam but also to applied magnetic field. Higher energy gain in GeV range is seen with higher mode indices in the presence of applied magnetic field. The obtained results with distinct TEM modes would be helpful in the development of better table top accelerators of diverse needs.

scholarly journals TEM modes influenced electron acceleration by Hermite–Gaussian laser beam in plasma

2016 ◽  
Vol 34 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Harjit Singh Ghotra ◽  
Niti Kant
Keyword(s):  
Laser Beam ◽  
Beam Width ◽  
Electron Acceleration ◽  
Particle Simulation ◽  
Electron Interaction ◽  
Electron Dynamics ◽  
Gaussian Laser Beam ◽  
Trapping Force ◽  
Tem Mode ◽  
Transverse Electromagnetic

AbstractElectron acceleration by a circularly polarized Hermite–Gaussian (HG) laser beam in the plasma has been investigated theoretically for the different transverse electromagnetic (TEM) mode indices (m, n) as (0, 1), (0, 2), (0, 3), and (0, 4). HG laser beam possesses higher trapping force compared with a standard Gaussian beam owing to its propagation characteristics during laser–electron interaction. A single-particle simulation indicates a resonant enhancement in the electron acceleration with HG laser beam. We present the intensity distribution for different TEM modes. We also analyze the dependence of beam width parameter on electron acceleration distance, which effectively influences the electron dynamics. Electron acceleration up to longer distance is observed with the lower modes. However, the higher electron energy gain is observed with higher modes at shorter distance of propagation.

scholarly journals Terahertz radiation by self-focused amplitude-modulated Gaussian laser beam in magnetized ripple density plasma

2015 ◽  
Vol 33 (4) ◽  
pp. 741-747 ◽  
Author(s):  
Ram Kishor Singh ◽  
R. P. Sharma
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Applied Magnetic Field ◽  
Magnetized Plasma ◽  
Thz Radiation ◽  
Gaussian Laser Beam ◽  
Spatial Profile ◽  
Self Focusing ◽  
Oscillatory Velocity ◽  
Density Plasma

AbstractThis paper presents a theoretical model for efficient terahertz (THz) radiation by self-focused amplitude-modulated laser beam in preformed ripple density plasma. The density of plasma is modified due to ponderomotive nonlinearity which arises because of the nonuniform spatial profile of the laser beam in magnetized plasma and leads to the self-focusing of the laser beam. The rate of self-focusing depends on the intensity of the amplitude-modulated beam as well as on the externally applied magnetic field strength. The electron also experiences time-dependent ponderomotive force by the laser beam at modulated frequency. A nonlinear current at THz frequency arises on account of the coupling between the ripple density plasma and nonlinear oscillatory velocity of the electrons. The yield of the generated THz radiation enhances with enhancement in self-focusing of the laser beam and applied magnetic field.

Basic features of a charged particle dynamics in a laser beam with static axial magnetic field

2009 ◽  
Vol 17 (4) ◽  
Author(s):  
A. Dubik ◽  
M.J. Małachowski
Keyword(s):  
Magnetic Field ◽  
Charged Particle ◽  
Kinetic Energy ◽  
Electric Field ◽  
Laser Beam ◽  
Analytical Solutions ◽  
Axial Magnetic Field ◽  
Dynamic Equations ◽  
Graphical Form ◽  
Particle Rotation

AbstractIn this paper, the trajectory and kinetic energy of a charged particle, subjected to interaction from a laser beam containing an additionally applied external static axial magnetic field, have been analyzed. We give the rigorous analytical solutions of the dynamic equations. The obtained analytical solutions have been verified by performing calculations using the derived solutions and the well known Runge-Kutta procedure for solving original dynamic equations. Both methods gave the same results. The simulation results have been obtained and presented in graphical form using the derived solutions. Apart from the laser beam, we show the results for a maser beam. The obtained analytical solutions enabled us to perform a quantitative illustration, in a graphical form of the impact of many parameters on the shape, dimensions and the motion direction along a trajectory. The kinetic energy of electrons has also been studied and the energy oscillations in time with a period equal to the one of a particle rotation have been found. We show the appearance of, so-called, stationary trajectories (hypocycloid or epicycloid) which are the projections of the real trajectory onto the (x, y) plane. Increase in laser or maser beam intensity results in the increase in particle’s trajectory dimension which was found to be proportional to the amplitude of the electric field of the electromagnetic wave. However, external magnetic field increases the results in shrinking of the trajectories. Performed studies show that not only amplitude of the electric field but also the static axial magnetic field plays a crucial role in the acceleration process of a charged particle.At the authors of this paper best knowledge, the precise analytical solutions and theoretical analysis of the trajectories and energy gains by the charged particles accelerated in the laser beam and magnetic field are lacking in up to date publications. The authors have an intention to clarify partly some important aspects connected with this process. The presented theoretical studies apply for arbitrary charged particle and the attached figures-for electrons only.

Spot-size evolution of laser beam propagating in plasma embedded in axial magnetic field

2007 ◽  
Vol 14 (11) ◽  
pp. 114504 ◽  
Author(s):  
Pallavi Jha ◽  
Rohit K. Mishra ◽  
Ajay K. Upadhyay ◽  
Gaurav Raj
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Axial Magnetic Field ◽  
Spot Size ◽  
Size Evolution

scholarly journals Magnetically Induced Carrier Distribution in a Composite Rod of Piezoelectric Semiconductors and Piezomagnetics

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3115 ◽  
Author(s):  
Guolin Wang ◽  
Jinxi Liu ◽  
Wenjie Feng ◽  
Jiashi Yang
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Axial Magnetic Field ◽  
Semiconductor Layer ◽  
Carrier Distribution ◽  
Composite Rod ◽  
Piezoelectric Effects ◽  
Potential Applications ◽  
Piezoelectric Coupling ◽  
Piezoelectric Semiconductors

In this work, we study the behavior of a composite rod consisting of a piezoelectric semiconductor layer and two piezomagnetic layers under an applied axial magnetic field. Based on the phenomenological theories of piezoelectric semiconductors and piezomagnetics, a one-dimensional model is developed from which an analytical solution is obtained. The explicit expressions of the coupled fields and the numerical results show that an axially applied magnetic field produces extensional deformation through piezomagnetic coupling, the extension then produces polarization through piezoelectric coupling, and the polarization then causes the redistribution of mobile charges. Thus, the composite rod exhibits a coupling between the applied magnetic field and carrier distribution through combined piezomagnetic and piezoelectric effects. The results have potential applications in piezotronics when magnetic fields are relevant.

scholarly journals Effects of plasma electron temperature and magnetic field on the propagation dynamics of Gaussian laser beam in weakly relativistic cold quantum plasma

2019 ◽  
Vol 37 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Munish Aggarwal ◽  
Vimmy Goyal ◽  
Richa Kashyap ◽  
Harish Kumar ◽  
Tarsem Singh Gill
Keyword(s):  
Magnetic Field ◽  
Laser Beam ◽  
Electron Temperature ◽  
Axial Magnetic Field ◽  
Beam Width ◽  
Plasma Electron ◽  
Quantum Plasma ◽  
Gaussian Laser Beam ◽  
Self Focusing ◽  
Initial Plasma

AbstractSelf-focusing of Gaussian laser beam has been investigated in quantum plasma under the effect of applied axial magnetic field. The nonlinear differential equation has been derived for studying the variations in the beam-width parameter. The effect of initial plasma electron temperature and the axial magnetic field on self-focusing and normalized intensity are studied. Our investigation reveals that normalized intensity increases to tenfolds where quantum effects are dominant. The normalized intensity further increases to twelvefolds on increasing the magnetic field.

scholarly journals Subnanosecond breakdown of air-insulated coaxial line initiated by runaway electrons in the presence of a strong axial magnetic field

2021 ◽  
Vol 2064 (1) ◽  
pp. 012003
Author(s):  
G A Mesyats ◽  
E A Osipenko ◽  
K A Sharypov ◽  
V G Shpak ◽  
S A Shunailov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Voltage Pulse ◽  
Plasma Layer ◽  
Axial Magnetic Field ◽  
Coaxial Line ◽  
Runaway Electrons ◽  
Cathode Plasma ◽  
Fast Electrons

Abstract Flow of runaway electrons (RAEs) propagating in a radial, air-filled gap of coaxial line (CL) changes the dynamics of breakdown in the field of traveling voltage pulse. However, despite the effect of RAEs, breakdown does not occur if subnanosecond pulse is less in duration and amplitude than some values. In this work, we study the influence of an external axial magnetic field (B z) on the breakdown development. We demonstrate the transformation of the voltage pulse reflection from the ionized (breakdown) zone with changing B z. Due to gyration of fast electrons in an applied magnetic field, the gas region ionized by RAEs does not reach the anode. The ionized bridge between the cathode and anode is gradually replaced by a near-cathode plasma layer representing a discrete, reflecting/absorbing inhomogeneity in the CL.

Segregation During Magnetically-Stabilized Liquid-Encapsulated Growth of Compound Semiconductor Crystals

2000 ◽  
Author(s):  
Nancy Ma ◽  
David F. Bliss ◽  
George G. Bryant
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Applied Magnetic Field ◽  
Dopant Concentration ◽  
Axial Magnetic Field ◽  
Compound Semiconductor ◽  
Semiconductor Crystal ◽  
Semiconductor Crystals ◽  
Single Compound ◽  
Relative Motions

Abstract During the magnetically-stabilized liquid-encapsulated Czochralski (MLEC) process, a single compound semiconductor crystal is grown by the solidification of an initially molten semiconductor (melt) contained in a crucible. The melt is doped with an element in order to vary the electrical and/or optical properties of the crystal. During growth, the so-called melt-depletion flow caused by the opposing relative motions of the encapsulant-melt interface and the crystal-melt interface can be controlled with an externally applied magnetic field. The convective dopant transport during growth driven by this melt motion produces non-uniformities of the dopant concentration in both the melt and the crystal. This paper presents a model for the unsteady transport of a dopant during the MLEC process with an axial magnetic field. Dopant distributions in the crystal and in the melt at several different stages during growth are presented.

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