scholarly journals Plasma channeling by multiple short-pulse lasers

2009 ◽  
Vol 27 (1) ◽  
pp. 109-114 ◽  
Author(s):  
W. Yu ◽  
L. Cao ◽  
M.Y. Yu ◽  
H. Cai ◽  
H. Xu ◽  
...  
Keyword(s):  
Ponderomotive Force ◽  
Laser Energy ◽  
Short Pulse ◽  
Laser Pulses ◽  
Particle In Cell ◽  
Peak Intensity ◽  
Cell Simulation ◽  
Short Pulse Lasers ◽  
Long Pulse ◽  
Similar Peak

AbstractChanneling by a train of laser pulses into homogeneous and inhomogeneous plasmas is studied using particle-in-cell simulation. When the pulse duration and the interval between the successive pulses are appropriate, the laser pulse train can channel into the plasma deeper than a single long-pulse laser of similar peak intensity and total energy. The increased penetration distance can be attributed to the repeated actions of the ponderomotive force, the continuous between-pulse channel lengthening by the inertially evacuating ions, and the suppression of laser-driven plasma instabilities by the intermittent laser-energy cut-offs.

scholarly journals Efficient acceleration of a small dense plasma pellet by consecutive action of multiple short intense laser pulses

2009 ◽  
Vol 27 (4) ◽  
pp. 629-634 ◽  
Author(s):  
X. Wang ◽  
W. Yu ◽  
M.Y. Yu ◽  
V.K. Senecha ◽  
H. Xu ◽  
...  
Keyword(s):  
Dense Plasma ◽  
Ponderomotive Force ◽  
Laser Pulses ◽  
Intense Laser ◽  
Energetic Ions ◽  
Practical Applications ◽  
Particle In Cell ◽  
High Speeds ◽  
Intense Laser Pulses ◽  
Cell Simulation

AbstractThe acceleration of a micrometer-sized plasma pellet at 100 critical densities (1023 cm−3) by consecutive application of ultra-short ultra-intense laser pulses is studied using two-dimensional particle-in-cell simulation. It is shown that due to the repeated actions of the laser ponderomotive force, a small dense plasma pellet can be efficiently accelerated, with a considerable fraction of the plasma ions accelerated to high speeds. The proposed scheme can provide a high-density flux of energetic ions, which should be valuable in many practical applications.

Compact Energy Measuring System for Short Pulse Lasers

2013 ◽  
Vol 20 (2) ◽  
pp. 183-190 ◽  
Author(s):  
A. Barna ◽  
I. B. Földes ◽  
Z. Gingl ◽  
R. Mingesz
Keyword(s):  
Short Pulse ◽  
Electronic Devices ◽  
Laser Pulses ◽  
Measuring System ◽  
Electric Response ◽  
Usb Interface ◽  
Radiated Noise ◽  
Fiber Optical ◽  
Measurement Control ◽  
Short Pulse Lasers

Abstract In experiments with short-pulse lasers the measurement control of the energy of the laser pulse is of crucial importance. Generally it is difficult to measure the amplitude of the pulses of short-pulse lasers using electronic devices, their response time being longer than the duration of the laser pulses. The electric response of the detector is still too fast to be directly digitized therefore a peak-hold unit can be used to allow data processing for the computer. In this paper we present a device which measures the energy of UV short (fs) pulses shot-byshot, digitizes and sends the data to the PC across an USB interface. The circuit is based on an analog peak detect and hold unit and the use of fiber optical coupling between the PC and the device provides a significant improvement to eliminate potential ground loops and to reduce conductive and radiated noise as well. The full development is open source and has been made available to download from our web page (http://www.noise.inf.u-szeged.hu/Instruments/PeakHold/).

Optical diagnostics of laser-produced plasmas with ultra-short laser pulses

1980 ◽  
Vol 298 (1439) ◽  
pp. 407-414 ◽  
Keyword(s):  
Short Pulse ◽  
Laser Pulses ◽  
Laser Fusion ◽  
Light Pressure ◽  
Laser Plasma Interaction ◽  
Short Laser Pulses ◽  
Short Pulse Lasers ◽  
Pellet Density ◽  
Laser Heated ◽  
Interaction Problem

In laser fusion experiments the interesting phenomena occur on a picosecond timescale. Short-pulse lasers in combination with high resolution optics offer a powerful diagnostic tool. After a short description of the principles and experimental techniques I discuss three specific areas of the laser-plasma interaction problem, namely heat transport in the corona of a laser heated pellet, density profile steepening by light pressure and the generation of magnetic fields.

scholarly journals Development of a 1 TW/35 fs Ti:sapphire Laser Amplifier and Generation of Intense THz Waves Using Two-Color Laser Filamentation

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 316
Author(s):  
Vanessa Ling Jen Phung ◽  
Keekon Kang ◽  
Seongjin Jeon ◽  
Jinju Kim ◽  
Kyungmin Roh ◽  
...  
Keyword(s):  
Laser Energy ◽  
Second Harmonic ◽  
Laser Pulses ◽  
Intense Laser ◽  
Laser Amplifier ◽  
Terahertz Waves ◽  
Regenerative Amplifier ◽  
Central Wavelength ◽  
Particle In Cell ◽  
Ti:Sapphire Laser

We developed a compact Ti:sapphire laser amplifier system in our laboratory, generating intense laser pulses with a peak power of >1 TW (terawatt), a pulse duration of 34 fs (femtosecond), a central wavelength of 800 nm, and a repetition rate of 10 Hz. The laser amplifier system consists of a mode-locked Ti:sapphire oscillator, a regenerative amplifier, and a single-side-pumped 4-pass amplifier. The chirped-pulse amplification (CPA)-based laser amplifier was found to provide an energy of 49.6 mJ after compression by gratings in air, where the pumping fluence of 1.88 J/cm2 was used. The amplified spontaneous emission (ASE) level was measured to be lower than 10−7, and ps-prepulses were in 10−4 or lower level. The developed laser amplifier system was used for the generation of intense THz (terahertz) waves by focusing the original (800 nm) and second harmonic (400 nm) laser pulses in air. The THz pulse energy was shown to be saturated in the high laser energy regime, and this phenomenon was confirmed by fully electromagnetic, relativistic, and self-consistent particle-in-cell (PIC) simulations.

scholarly journals Effect of pre-plasma on the ion acceleration by intense ultra-short laser pulses

2018 ◽  
Vol 36 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Parvin Varmazyar ◽  
Saeed Mirzanejhad ◽  
Taghi Mohsenpour
Keyword(s):  
Laser Pulses ◽  
Complete Analysis ◽  
Ion Acceleration ◽  
Destructive Effect ◽  
Particle In Cell ◽  
Solid Density ◽  
Cell Simulation ◽  
Fs Laser ◽  
Short Laser Pulses ◽  
Plasma Effect

AbstractIn the interaction of short-laser pulses with a solid density target, pre-plasma can play a major role in ion acceleration processes. So far, complete analysis of pre-plasma effect on the ion acceleration by ultra-short laser pulses in the radiation pressure acceleration (RPA) regime has been unknown. Then the effect of pre-plasma on the ion acceleration efficiency is analyzed by numerical results of the particle-in-cell simulation in the RPA regime. It is shown that, for long-laser pulses (τp > 50 fs), the presence of pre-plasma makes a destructive effect on ion acceleration while it may have a contributing effect for short-laser pulses (τp < 50 fs). Therefore, the 35 fs (20 fs) laser pulse can accelerate ions up to 40 MeV (55 eV), which is almost two (three) times larger in energy rather than use of a 100 fs pulse with the same pre-plasma scale length.

Polarization dependence of optical harmonic generation from solid targets at high intensities: Role of Faraday rotation

2002 ◽  
Vol 80 (2) ◽  
pp. 173-177
Author(s):  
S Wu ◽  
R -J Zhan ◽  
J Chen
Keyword(s):  
Magnetic Field ◽  
Faraday Rotation ◽  
Short Pulse ◽  
Yield Ratio ◽  
Particle In Cell ◽  
Cell Simulation ◽  
Optical Harmonic Generation ◽  
Optical Harmonic ◽  
Good Agreement

In this letter, we show that the Faraday rotation effect of the strong spontaneous magnetic field generated by the focus of a short-pulse, high-power laser interacting with a solid target may blur out the distinction between the s and p polarization of the incident laser. This in effect leads to the result that the harmonic yield ratio between p and s polarization is not as large as a PIC (particle-in-cell) simulation predicted. An approximate calculation of the harmonic yield ratio versus the magnetic field is carried out and the result is in relatively good agreement with the observations by Norreys et al. PACS Nos.: 42.90, 78.90

scholarly journals Diagnostics of peak laser intensity based on the measurement of energy of electrons emitted from laser focal region

2015 ◽  
Vol 33 (3) ◽  
pp. 361-366 ◽  
Author(s):  
M. Kalashnikov ◽  
A. Andreev ◽  
K. Ivanov ◽  
A. Galkin ◽  
V. Korobkin ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Laser Pulses ◽  
Maximum Energy ◽  
Beam Waist ◽  
Focal Region ◽  
Low Density ◽  
Particle In Cell ◽  
Peak Intensity ◽  
Low Density Plasma ◽  
Density Plasma

AbstractA new method to determine the peak intensity of focused relativistic laser pulses is experimentally justified. It is based on the measurement of spectra of electrons, accelerated in the beam waist. The detected electrons were emitted from the plasma, generated by nonlinear ionization of low-density gases (helium, argon, and krypton) in the focal area of a laser beam with the peak intensity >1020 W/cm2. The measurements revealed generation of particles with the maximum energy of a few MeV, observed at a small angle relative to the beam axis. The results are supported by numerical particle-in-cell simulations of a laser–low-density plasma interaction. The peak intensity in the focal region derived from experimental data reaches the value of 2.5 × 1020 W/cm2.

scholarly journals Physics of short pulse laser plasma interaction by multi-dimensional particle-in-cell simulations

1999 ◽  
Vol 17 (3) ◽  
pp. 571-578 ◽  
Author(s):  
A. PUKHOV ◽  
J. MEYER-TER-VEHN
Keyword(s):  
Short Pulse ◽  
Laser Pulses ◽  
Laser Plasma Interaction ◽  
Particle In Cell ◽  
Wake Field ◽  
Short Pulse Laser ◽  
Direct Laser ◽  
Underdense Plasmas ◽  
Laser Pulse Power ◽  
Overdense Plasma

Interaction of relativistically strong laser pulses with under- and overdense plasmas is studied by 3D particle-in-cell simulations. We show that electrons in the underdense plasmas can be accelerated not only by the plasma wake field, but also by direct laser push in self-generated magnetic and electrostatic fields. These two mechanisms of acceleration manifest themselves in the electron energy spectra as two effective “temperatures.” We show that the fast electrons transport a significant part of the laser pulse power through the overdense plasma in the form of magnetized jets. We also find high collective stopping because of an anomalous resistivity of the plasma.

STRONG LASER FIELD INTERACTION WITH DIATOMIC MOLECULES: FROM THE ULTRA-SHORT TO LONG-PULSE REGIME

1995 ◽  
Vol 04 (04) ◽  
pp. 817-829 ◽  
Author(s):  
M. SCHMIDT ◽  
P. D'OLIVEIRA ◽  
P. MEYNADIER ◽  
D. NORMAND ◽  
C. CORNAGGIA
Keyword(s):  
Short Pulse ◽  
Laser Pulses ◽  
Pulse Regime ◽  
Strong Laser Field ◽  
Pulse Experiment ◽  
Femtosecond Regime ◽  
Ultra Short Pulse ◽  
Long Pulse ◽  
First Time ◽  
Coulomb Energies

In the present paper, we compare novel MEDI results on iodine obtained with 30 ps laser pulses to those obtained in the femtosecond regime. The results indicate laser-induced trapping of the molecules not only in the ultra-short pulse regime, but also for the long pulses, since the fragment kinetic energy releases are essentially the same, although the pulse duration is varied over more than two orders of magnitude. Most interestingly, with 30 ps pulses significant post-dissociation ionization of the In+-fragments observed for the first time, proving that near-Coulomb energies and post-dissociation ionization can be observed simultaneously. A femtosecond double-pulse experiment confirms our recent hypothesis of molecular stabilization governing the MEDI interaction.

Sign in / Sign up

Export Citation Format

Share Document