Wakefield stimulated terahertz radiation from a plasma grating

2021 ◽  
Author(s):  
Götz Lehmann ◽  
Karl Heinz Spatschek
Keyword(s):  
Laser Pulse ◽  
Plasma Frequency ◽  
Laser Pulses ◽  
Short Laser Pulse ◽  
Wave Radiation ◽  
Similar Frequency ◽  
Emission Process ◽  
Particle In Cell ◽  
Volume Emission ◽  
Electromagnetic Instability

Abstract When a short laser pulse propagates in a corrugated plasma, its wakefield interacts with the density and electric field ripples of the plasma. In the present paper, the modulation of the plasma originates from two counter-propagating long laser pulses, i.e. the corrugated plasma can be as- sumed as a so called plasma grating. PIC (particle in cell) simulations show electromagnetic wave radiation at a frequency just above the plasma frequency when the wakefield interacts with the grating. An electromagnetic instability is proposed as the reason for the emission process. The electrostatic driver of the electromagnetic instability is the beat of wake and grating. That beat mode possess large wavenumber (originating from the small grating wavelength) and small fre- quency (of the order of the plasma frequency) when one concentrates on small ratios of the plasma modulation length to the wavelength of the wakefield. The latter situation occurs when the long laser pulses (which generate the grating) as well as the short laser pulse (which drives the wakefield) have similar frequency ω0 ≫ ωpe where ωpe is the plasma frequency. The coherent volume emission process lasts for a while. It is finally superseded by terahertz transition radiation at the boundaries of the original grating.

ENERGETIC PROTON ACCELERATION BY ULTRAINTENSE LASER PULSES IN INHOMOGENEOUS PLASMA TARGETS

2007 ◽  
Vol 21 (03n04) ◽  
pp. 642-646 ◽  
Author(s):  
A. ABUDUREXITI ◽  
Y. MIKADO ◽  
T. OKADA
Keyword(s):  
Laser Pulse ◽  
Inhomogeneous Plasma ◽  
Laser Pulses ◽  
Proton Acceleration ◽  
Particle In Cell ◽  
Target Plasma ◽  
Plasma Target ◽  
Experimental Process ◽  
Foil Target ◽  
Proton Bunch

Particle-in-Cell (PIC) simulations of fast particles produced by a short laser pulse with duration of 40 fs and an intensity of 1020W/cm2 interacting with a foil target are performed. The experimental process is numerically simulated by considering a triangular concave target illuminated by an ultraintense laser. We have demonstrated increased acceleration and higher proton energies for triangular concave targets. We also determined the optimum target plasma conditions for maximum proton acceleration. The results indicated that a change in the plasma target shape directly affects the degree of contraction accelerated proton bunch.

scholarly journals Theoretical model for heat conduction in metals during interaction with ultra short laser pulse

2006 ◽  
Vol 24 (3) ◽  
pp. 347-353 ◽  
Author(s):  
MUHAMMAD SHAHBAZ ANWAR ◽  
ANWAR LATIF ◽  
M. IQBAL ◽  
M. SHAHID RAFIQUE ◽  
M. KHALEEQ-UR-RAHMAN ◽  
...  
Keyword(s):  
Heat Conduction ◽  
Theoretical Model ◽  
Laser Pulse ◽  
Current Density ◽  
Laser Pulses ◽  
Short Laser Pulse ◽  
Short Laser Pulses ◽  
Electronic Heat ◽  
Target Metal ◽  
Electromagnetic Radiations

Theoretical studies have been performed on the interaction of short laser pulse with metals. The results of the theoretical model indicate that heat conduction would not be uniform from focal spot or crater at the surface of target metal, when an ultra short laser will interact with the metal. The electromagnetic radiations of laser induce electric field inside the target that is responsible for the induction of current density, which causes electronic heat conduction in the direction of current density. Such an effect is dominant for laser pulse having duration less than of the order of sub-picoseconds. This mode will open a new significant field of study to discuss laser metal interaction for ultra short laser pulses.

scholarly journals Ionization-induced leaking-mode channeling of intense short laser pulses in gases

1999 ◽  
Vol 17 (1) ◽  
pp. 129-138 ◽  
Author(s):  
A.M. SERGEEV ◽  
M. LONTANO ◽  
A.V. KIM ◽  
V.B. GILDENBURG ◽  
M.D. CHERNOBROVTSEVA ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Plasma Channel ◽  
Computational Study ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Short Laser Pulse ◽  
Saturation Regime ◽  
Short Laser Pulses ◽  
Ultrashort Laser ◽  
Guiding Effect

We demonstrate that short laser pulse self-guiding over distances of many Rayleigh lengths can be achieved in the absence of any focusing nonlinearity as a result of trapping of a leaking wave in a plasma channel produced by field-induced ionization in the saturation regime. A detailed computational study of the new self-guiding effect in both cases of comparatively long laser pulses, when the traditional approximation of the slowly varying complex amplitude is valid, and of high intense ultrashort laser pulses comprising only few field cycles have been performed.

scholarly journals Ion motion effects on the generation of short-cycle relativistic laser pulses during radiation pressure acceleration

2014 ◽  
Vol 2 ◽  
Author(s):  
W. P. Wang ◽  
X. M. Zhang ◽  
X. F. Wang ◽  
X. Y. Zhao ◽  
J. C. Xu ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Radiation Pressure ◽  
Analytical Modeling ◽  
Laser Pulses ◽  
Short Cycle ◽  
Ion Motion ◽  
Particle In Cell ◽  
Rear Part ◽  
Fs Laser ◽  
Bubble Regime

AbstractThe effects of ion motion on the generation of short-cycle relativistic laser pulses during radiation pressure acceleration are investigated by analytical modeling and particle-in-cell simulations. Studies show that the rear part of the transmitted pulse modulated by ion motion is sharper compared with the case of the electron shutter only. In this study, the ions further modulate the short-cycle pulses transmitted. A 3.9 fs laser pulse with an intensity of $1.33\times 10^{21}\ {\rm W}\ {\rm cm}^{-2}$ is generated by properly controlling the motions of the electron and ion in the simulations. The short-cycle laser pulse source proposed can be applied in the generation of single attosecond pulses and electron acceleration in a small bubble regime.

scholarly journals Wakefield generation and electron acceleration by intense super-Gaussian laser pulses propagating in plasma

2013 ◽  
Vol 31 (4) ◽  
pp. 583-588 ◽  
Author(s):  
Pallavi Jha ◽  
Akanksha Saroch ◽  
Rohit Kumar Mishra
Keyword(s):  
Laser Pulse ◽  
Laser Pulses ◽  
Gaussian Pulse ◽  
Simulation Studies ◽  
One Dimensional ◽  
Particle In Cell ◽  
Peak Energy ◽  
Test Electron ◽  
Linearly Polarized ◽  
Relativistic Regime

AbstractEvolution of longitudinal electrostatic wakefields, due to the propagation of a linearly polarized super-Gaussian laser pulse through homogeneous plasma has been presented via two-dimensional particle-in-cell simulations. The wakes generated are compared with those generated by a Gaussian laser pulse in the relativistic regime. Further, one-dimensional numerical model has been used to validate the generated wakefields via simulation studies. Separatrix curves are plotted to study the trapping and energy gain of an externally injected test electron, due to the generated electrostatic wakefields. An enhancement in the peak energy of an externally injected electron accelerated by wakes generated by super-Gaussian pulse as compared to Gaussian pulse case has been observed.

scholarly journals Ion acceleration in overdense plasma by short laser pulse

2004 ◽  
Vol 22 (2) ◽  
pp. 175-181 ◽  
Author(s):  
O. SHOROKHOV ◽  
A. PUKHOV
Keyword(s):  
Laser Pulse ◽  
Double Layer ◽  
Front Surface ◽  
Ion Trapping ◽  
Short Laser Pulse ◽  
Ion Acceleration ◽  
Proton Acceleration ◽  
Particle In Cell ◽  
Overdense Plasma ◽  
Background Ions

We consider ion acceleration at the front surface of overdense plasma by a short laser pulse. In this configuration, the laser ponderomotive pressure pushes the background electrons, and a double layer is produced at the boundary of the overdense region. The ions are accelerated by the electrostatic field of the double layer. If the laser intensity is so large that the plasma becomes relativistically transparent, then ion trapping in the running double layer and acceleration to relativistic energies is possible. We study this physics using one-dimensional particle-in-cell simulations. Ion acceleration in one- and two-component plasmas is considered. It is shown that the proton acceleration is more effective when they represent only a small dope to the heavy background ions.

scholarly journals Laser-ablation and induced nanoparticle synthesis

2013 ◽  
Vol 32 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Dimitri Batani ◽  
Tommaso Vinci ◽  
Davide Bleiner
Keyword(s):  
Laser Ablation ◽  
Equation Of State ◽  
Laser Pulse ◽  
Computer Simulations ◽  
Nanoparticle Synthesis ◽  
Laser Pulses ◽  
Skin Depth ◽  
Short Laser Pulse ◽  
Nano Materials ◽  
Nano Particle

AbstractLaser pulses are largely used for processing and analysis of materials and in particular for nano-particle synthesis. This paper addresses fundamentals of the generation of nano-materials following specific thermodynamic paths of the irradiated material. Computer simulations using the hydro code MULTI and the SESAME equation of state have been performed to follow the dynamics of a target initially heated by a short laser pulse over a distance comparable to the metal skin depth.

Light-Induced Degradation of a-Si:H - A Comparison of Short-Laser-Pulse and Steady Light Degradation

1995 ◽  
Vol 377 ◽  
Author(s):  
P. Tzanetakis ◽  
N. Kopidakis ◽  
M. Androulidakp ◽  
C. Kalpouzos ◽  
P. Stradins ◽  
...  
Keyword(s):  
Low Temperature ◽  
Laser Pulse ◽  
Laser Pulses ◽  
Defect Concentration ◽  
Short Laser Pulse

ABSTRACTAn undoped and a compensated a-Si:H sample have been degraded by 17–34 ns laser pulses and by steady light (CW) at 78K and 300K. The light-induced defect concentration N is monitored by the increase in subgap absorption a. For the same change in a pulses degrade the photoconductivity σp more than CW light and more strongly for exposures at 78K than at 300K. The lack of correlation between σp and N suggests that light soaking causes additional damage besides an increase in N. This additional effect is more pronounced for pulse and low temperature exposures.

scholarly journals Nonlinear electromagnetic phenomena in the relativistic interaction of ultrahigh intensity laser pulses with plasmas

2000 ◽  
Vol 18 (3) ◽  
pp. 381-387 ◽  
Author(s):  
F. PEGORARO ◽  
S.V. BULANOV ◽  
F. CALIFANO ◽  
T.ZH. ESIRKEPOV ◽  
T.V. LISEIKINA ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Low Frequency ◽  
Laser Pulses ◽  
Energy Depletion ◽  
Particle In Cell ◽  
Ultrarelativistic Electron ◽  
Relativistic Interaction ◽  
Underdense Plasmas ◽  
Plasma Pulse ◽  
Intensity Laser

2D, low-frequency, relativistic solitary waves have been found recently in 2D. Particle-in-cell simulations of ultraintense laser pulses propagating in underdense plasmas, in regimes where the laser pulse undergoes energy depletion and downshifting of its frequency. These slowly propagating, spatially localized, electromagnetic structures represent an important channel of energy conversion from the laser pulse to the plasma. Pulse energy can also be converted into fast propagating structures, associated with collimated beams of ultrarelativistic electrons. Lienard–Wiechert magnetic field structures have been observed in PIC simulations to move together with focalized ultrarelativistic electron beams in the plasma.

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