scholarly journals Linear and nonlinear absolute phase effects in interactions of ulrashort laser pulses with a metal nano-layer or with a thin plasma layer

2007 ◽  
Vol 25 (3) ◽  
pp. 379-390 ◽  
Author(s):  
S. Varró
Keyword(s):  
Laser Pulse ◽  
Phase Difference ◽  
Plasma Layer ◽  
Thin Foil ◽  
Laser Pulses ◽  
Thomson Scattering ◽  
Carrier Envelope Phase ◽  
Absolute Phase ◽  
High Intensity Laser ◽  
Order Of Magnitude

It has been shown that in the scattered radiation, generated by an ultrashort laser pulse impinging on a metal nano-layer, non-oscillatory wakefields appears with a definite sign. The magnitude of these wakefields is proportional to the incoming field strength, and the definite sign of them is governed by the cosine of the carrier-envelope phase difference of the incoming pulse. When we let such a Wakefield excite the electrons of a secondary target (say an electron beam, a metal surface or a gas jet), we can obtain 100 percent modulation in the electron signal in a given direction. This scheme can serve as a basis for the construction of a robust linear carrier-envelope phase difference meter. At relativistic laser intensities, the target is considered as a plasma layer in vacuum produced from a thin foil by a prepulse, which is followed by the main high-intensity laser pulse. The nonlinearities stemming from the relativistic kinematics lead to the appearance of higher-order harmonics in the scattered spectra. In general, the harmonic peaks are downshifted due to the presence of an intensity-dependent factor. This phenomenon is analogous to the famous intensity-dependent frequency shift in the nonlinear Thomson scattering on a single electron. In our analysis, an attention has also been paid to the role of the carrier-envelope phase difference of the incoming few-cycle laser pulse. It is also shown that the spectrum has a long tail where the heights of the peaks vary practically within one order of magnitude forming a quasi-continuum. Fourier synthesizing the components from this plateau region attosecond pulses has obtained.

scholarly journals Signatures of the Carrier Envelope Phase in Nonlinear Thomson Scattering

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 528
Author(s):  
Marcel Ruijter ◽  
Vittoria Petrillo ◽  
Thomas C. Teter ◽  
Maksim Valialshchikov ◽  
Sergey Rykovanov
Keyword(s):  
Laser Pulse ◽  
Radiation Spectrum ◽  
Thomson Scattering ◽  
High Energy ◽  
Phase Changes ◽  
High Energy Radiation ◽  
Carrier Envelope Phase ◽  
High Intensity Laser ◽  
Experimental Parameters ◽  
Intensity Laser

High-energy radiation can be generated by colliding a relativistic electron bunch with a high-intensity laser pulse—a process known as Thomson scattering. In the nonlinear regime the emitted radiation contains harmonics. For a laser pulse whose length is comparable to its wavelength, the carrier envelope phase changes the behavior of the motion of the electron and therefore the radiation spectrum. Here we show theoretically and numerically the dependency of the spectrum on the intensity of the laser and the carrier envelope phase. Additionally, we also discuss what experimental parameters are required to measure the effects for a beamed pulse.

scholarly journals High-intensity laser-driven proton acceleration: influence of pulse contrast

2006 ◽  
Vol 364 (1840) ◽  
pp. 711-723 ◽  
Author(s):  
Paul McKenna ◽  
Filip Lindau ◽  
Olle Lundh ◽  
David Neely ◽  
Anders Persson ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Thin Foil ◽  
Laser Pulses ◽  
Energy Distributions ◽  
Proton Acceleration ◽  
High Intensity Laser ◽  
Short Laser Pulses ◽  
Spatial Quality ◽  
Intensity Laser ◽  
Pulse Contrast

Proton acceleration from the interaction of ultra-short laser pulses with thin foil targets at intensities greater than 10 18  W cm −2 is discussed. An overview of the physical processes giving rise to the generation of protons with multi-MeV energies, in well defined beams with excellent spatial quality, is presented. Specifically, the discussion centres on the influence of laser pulse contrast on the spatial and energy distributions of accelerated proton beams. Results from an ongoing experimental investigation of proton acceleration using the 10 Hz multi-terawatt Ti : sapphire laser (35 fs, 35 TW) at the Lund Laser Centre are discussed. It is demonstrated that a window of amplified spontaneous emission (ASE) conditions exist, for which the direction of proton emission is sensitive to the ASE-pedestal preceding the peak of the laser pulse, and that by significantly improving the temporal contrast, using plasma mirrors, efficient proton acceleration is observed from target foils with thickness less than 50 nm.

scholarly journals Tc-99m production with ultrashort intense laser pulses

2014 ◽  
Vol 32 (4) ◽  
pp. 605-611 ◽  
Author(s):  
V. Yu. Bychenkov ◽  
A. V. Brantov ◽  
G. Mourou
Keyword(s):  
Laser Pulse ◽  
Thin Foil ◽  
Laser Pulses ◽  
High Energy ◽  
Intense Laser ◽  
Pic Simulation ◽  
Intense Laser Pulses ◽  
Fs Laser ◽  
Proton Generation ◽  
Coherent Amplification

AbstractThe interaction of a relativistic short laser pulse with thin foil is studied using 3D PIC simulations in the context of optimized high-energy proton generation for nuclear medicine and pharmacy. As an example, we analyze the Tc-99m yield from the Mo-100(p,2n)Tc-99m reaction with the International Coherent Amplification Network (ICAN) concept defined by a 10 J pulse energy and 10 kHz repetition rate. Based on 3D PIC simulation it has been demonstrated that normally incident 100 fs laser pulse with maximum intensity of 5 × 1021 W/cm2 is able to generate 1011 protons with energy upto 45 MeV from thin semi-transparent CH2 target. Such laser-produced proton beam after 6 hours bombardment of the thick metallic Mo-100 target gives around 300 Gbq activities of Tc-99m isotope. This gives reason to believe that laser technology for producing technetium is possible with ICAN concept to replace the traditional scheme through the fission of weapons-grade uranium.

scholarly journals Plasma guiding using a chaperone pre-pulse for stable wakefield generation

2021 ◽  
Author(s):  
Devki Nandan Gupta ◽  
Samuel Robert Yoffe ◽  
Arohi Jain ◽  
Bernhard Ersfeld ◽  
Dino Anthony Jaroszynski
Keyword(s):  
Laser Pulse ◽  
Laser Pulses ◽  
Space Distribution ◽  
Essential Step ◽  
Self Focusing ◽  
Radiation Sources ◽  
High Intensity Laser ◽  
Laser Wakefield ◽  
Intensity Laser ◽  
Wakefield Accelerators

Abstract Achieving high quality electron beams in laser wakefield accelerators requires stable guiding of the intense driving laser pulse, which is challenging because of mode mismatching due to relativistic self-focusing. Here we show how an intense pre-pulse can be used to prepare the phase-space distribution of plasma electrons encountered by a trailing laser pulse so that it produces its own well-matched guiding channel, while minimising wakefield evolution. Controlling the propagation of high intensity laser pulses is an essential step in developing useful wakefield accelerators and compact radiation sources.

Electron energy transport in the thin foil driven by high contrast high intensity laser pulse

2012 ◽  
Author(s):  
T. Tanimoto ◽  
M. Nishiuchi ◽  
Y. Mishima ◽  
K. Kikuyama ◽  
T. Morioka ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Electron Energy ◽  
High Intensity ◽  
Energy Transport ◽  
Thin Foil ◽  
High Contrast ◽  
High Intensity Laser ◽  
Intensity Laser

Generation of dense and well-collimated positron beam via ultra-intense laser colliding with a flying plasma layer

2021 ◽  
Author(s):  
QianQian Han ◽  
Xuesong Geng ◽  
Baifei Shen ◽  
Liangliang Ji ◽  
Zhizhan Xu
Keyword(s):  
Plasma Layer ◽  
Thin Foil ◽  
Positron Beam ◽  
Laser Pulses ◽  
Intense Laser ◽  
High Yield ◽  
Intensity Level ◽  
Electron Positron ◽  
Large Peak ◽  
Electron Positron Pair

Abstract With the forthcoming 10-100PW laser facilities, laser-driven electron-positron-pair production has gained particular interest. Here a scheme to enhance the generation of dense electron-positron-pairs is proposed and numerically demonstrated, employing double laser pulses at the intensity level of 10^23 W cm^(-2). The first laser accelerates a thin foil to a relativistic speed via the radiation-pressure-acceleration mechanism and a counter-propagating laser irradiates this flying plasma layer. The simulation results indicate that a high-yield and well-collimated positron beam (~5.5×10^10 positrons/pulse, 8.8nC/pulse) is generated with a large peak density(1.1×10^21 cm^(-3) ) by using tens-of-PW laser pulses.

RELATIVISTIC SELF-FOCUSING OF AN ULTRA-INTENSE LASER PULSE IN A PLASMA

1995 ◽  
Vol 04 (03) ◽  
pp. 547-566 ◽  
Author(s):  
G. MAINFRAY
Keyword(s):  
Laser Pulse ◽  
Thomson Scattering ◽  
Hydrogen Gas ◽  
Intense Laser ◽  
Gas Jet ◽  
Intense Laser Pulse ◽  
Self Focusing ◽  
Rayleigh Length ◽  
Relativistic Regime ◽  
Order Of Magnitude

New compact multiterawatt lasers allow us to study the relativistic regime of laserplasma interaction. The propagation of a multiterawatt subpicosecond laser pulse in a plasma has been investigated theoretically and experimentally. A 10 TW laser pulse at a 1064 nm wavelength has been focused in a hydrogen gas jet. Thomson scattering observations show that a relativistic self-focusing and channeling occur when the laser power exceeds a critical value predicted by theory. The amount of enhancement in self-focused intensity exceeds one order of magnitude. The laser pulse propagates through the plasma over a distance much larger than the Rayleigh length determined by vacuum diffraction.

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