scholarly journals Relativistic electron acceleration by surface plasma waves excited with high intensity laser pulses

2020 ◽  
Vol 8 ◽  
Author(s):  
X. M. Zhu ◽  
R. Prasad ◽  
M. Swantusch ◽  
B. Aurand ◽  
A. A. Andreev ◽  
...  
Keyword(s):  
Electron Flux ◽  
Incidence Angle ◽  
Laser Pulses ◽  
Electron Acceleration ◽  
High Energy ◽  
Laser Wavelength ◽  
Acceleration Process ◽  
Experimental Conditions ◽  
Preformed Plasma ◽  
Scale Length

The process of high energy electron acceleration along the surface of grating targets (GTs) that were irradiated by a relativistic, high-contrast laser pulse at an intensity $I=2.5\times 10^{20}~\text{W}/\text{cm}^{2}$ was studied. Our experimental results demonstrate that for a GT with a periodicity twice the laser wavelength, the surface electron flux is more intense for a laser incidence angle that is larger compared to the resonance angle predicted by the linear model. An electron beam with a peak charge of ${\sim}2.7~\text{nC}/\text{sr}$ , for electrons with energies ${>}1.5~\text{MeV}$ , was measured. Numerical simulations carried out with parameters similar to the experimental conditions also show an enhanced electron flux at higher incidence angles depending on the preplasma scale length. A theoretical model that includes ponderomotive effects with more realistic initial preplasma conditions suggests that the laser-driven intensity and preformed plasma scale length are important for the acceleration process. The predictions closely match the experimental and computational results.

scholarly journals Directional transport of fast electrons at the front target surface irradiated by intense femtosecond laser pulses with preformed plasma

2012 ◽  
Vol 30 (1) ◽  
pp. 39-43 ◽  
Author(s):  
X.X. Lin ◽  
Y.T. Li ◽  
B.C. Liu ◽  
F. Liu ◽  
F. Du ◽  
...  
Keyword(s):  
Electron Transport ◽  
Incidence Angle ◽  
Target Surface ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Fast Electrons ◽  
High Energy Electrons ◽  
Preformed Plasma ◽  
Directional Transport

AbstractThe effects of laser incidence angle on lateral fast electron transport at front target surface, when a plasma is preformed, irradiated by intense (>1018 W/cm2) laser pulses, are studied by Kα imaging technique and electron spectrometer. A horizontally asymmetric Kα halo, resulting from directional lateral electron transport and energy deposition, is observed for a large incidence angle (70°). Moreover, a group of MeV high energy electrons is emitted along target surface. It is believed that the deformed preplasma and the asymmetrical distribution of self-generated magnetic field, at large incidence angle, play an important role in the directional lateral electron transport.

scholarly journals Deep Penetration of UV Radiation into PMMA and Electron Acceleration in Long Plasma Channels Produced by 100 ns KrF Laser Pulses

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1883
Author(s):  
Vladimir D. Zvorykin ◽  
Sergei V. Arlantsev ◽  
Alexey V. Shutov ◽  
Nikolay N. Ustinovskii ◽  
Polad V. Veliev
Keyword(s):  
Specular Reflection ◽  
Laser Pulses ◽  
Electron Acceleration ◽  
High Energy ◽  
Deep Penetration ◽  
Axial Component ◽  
Axially Symmetric ◽  
Slowing Down ◽  
Krf Laser ◽  
Plasma Corona

Long (~1 mm), narrow (30−40 μm in diameter) corrugated capillary-like channels were produced in the axially symmetric 2D interaction regime of 100 ns KrF laser pulses with polymethylmethacrylate (PMMA) at intensities of up to 5 × 1012 W/cm2. The channels extended from the top of a deep (~1 mm) conical ablative crater and terminated in a 0.5 mm size crown-like pattern. The modeling experiments with preliminary drilled capillaries in PMMA targets and Monte Carlo simulations evidenced that the crown origin might be caused by high-energy (0.1–0.25 MeV) electrons, which are much higher than the electron temperature of the plasma corona ~100 eV. This indicates the presence of an unusual direct electron acceleration regime. Firstly, fast electrons are generated due to laser plasma instabilities favored by a long-length interaction of a narrow-band radiation with plasma in the crater. Then, the electrons are accelerated by an axial component of the electrical field in a plasma-filled corrugated capillary waveguide enhanced by radiation self-focusing and specular reflection at the radial plasma gradient, while channel ripples serve the slowing down of the electromagnetic wave in the phase with electrons.

scholarly journals Investigation of ultraintense femtosecond laser–plasma interactions through ω and 2ω imaging and spectroscopy

2001 ◽  
Vol 19 (1) ◽  
pp. 47-53 ◽  
Author(s):  
M. GALIMBERTI ◽  
A. GIULIETTI ◽  
D. GIULIETTI ◽  
L.A. GIZZI ◽  
PH. BALCOU ◽  
...  
Keyword(s):  
Laser Plasma ◽  
Second Harmonic ◽  
Electron Acceleration ◽  
Laser Frequency ◽  
High Energy ◽  
Preliminary Evidence ◽  
Wake Field ◽  
Imaging And Spectroscopy ◽  
Preformed Plasma ◽  
Femtosecond Laser Plasma

A laser–plasma interaction experiment was performed in order to match effective conditions for wake-field electron acceleration. A 30-fs pulse was made to interact with a preformed plasma generated via the exploding foil technique from a 1-μm-thick plastic film. The irradiance of the femtosecond pulse in the plasma was 1020 Wcm−2. The interaction conditions were investigated via imaging and spectroscopy at the fundamental and the second harmonic of the laser frequency, both forward and backward. Our data clearly show that conditions suitable for electron acceleration are achieved close to the propagation axis and can be easily reproduced from shot to shot. In contrast, significant growth of instabilities occurs at the boundaries of the interaction region. These observations are consistent with a preliminary evidence of forward acceleration of high-energy electrons. Optical, X-ray, and γ-ray data obtained for different positions of the foil target with respect to the laser focal plane further support this promising scenario.

Anisotropy of damage productions in electron irradiated molybdenum

1978 ◽  
Vol 36 (1) ◽  
pp. 354-355
Author(s):  
K. Izui ◽  
S. Furuno ◽  
H. Otsu ◽  
T. Nishida ◽  
H. Maeta
Keyword(s):  
Electron Flux ◽  
Threshold Energy ◽  
High Energy ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
Displacement Threshold ◽  
The Mean ◽  
Channeling Effect ◽  
Different Origins ◽  
Threshold Energies

Anisotropy of damage productions in crystals due to high energy electron bombardment are caused from two different origins. One is an anisotropic displacement threshold energy, and the other is an anisotropic distribution of electron flux near the atomic rows in crystals due to the electron channeling effect. By the n-beam dynamical calculations for germanium and molybdenum we have shown that electron flux at the atomic positions are from ∽4 to ∽7 times larger than the mean incident flux for the principal zone axis directions of incident 1 MeV electron beams, and concluded that such a locally increased electron flux results in an enhanced damage production. The present paper reports the experimental evidence for the enhanced damage production due to the locally increased electron flux and also the results of measurements of the displacement threshold energies for the <100>,<110> and <111> directions in molybdenum crystals by using a high voltage electron microscope.

scholarly journals Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

2019 ◽  
Vol 209 ◽  
pp. 01007
Author(s):  
Francesco Nozzoli
Keyword(s):  
Electron Flux ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Precision Measurements ◽  
High Energy Electrons ◽  
Electrons And Positrons ◽  
Positron Flux ◽  
Rigidity Dependence ◽  
Alpha Magnetic Spectrometer

Precision measurements by AMS of the fluxes of cosmic ray positrons, electrons, antiprotons, protons as well as their rations reveal several unexpected and intriguing features. The presented measurements extend the energy range of the previous observations with much increased precision. The new results show that the behavior of positron flux at around 300 GeV is consistent with a new source that produce equal amount of high energy electrons and positrons. In addition, in the absolute rigidity range 60–500 GV, the antiproton, proton, and positron fluxes are found to have nearly identical rigidity dependence and the electron flux exhibits different rigidity dependence.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

scholarly journals Concept of generation of extremely compressed high-energy electron bunches in several interfering intense laser pulses with tilted amplitude fronts

2012 ◽  
Vol 31 (1) ◽  
pp. 23-28 ◽  
Author(s):  
V.V. Korobkin ◽  
M.Yu. Romanovskiy ◽  
V.A. Trofimov ◽  
O.B. Shiryaev
Keyword(s):  
Laser Pulses ◽  
High Energy ◽  
Intense Laser ◽  
High Energy Electron ◽  
Speed Of Light ◽  
Electron Bunches ◽  
Newton Equation ◽  
High Energies ◽  
Neutral Gas ◽  
Intense Laser Pulses

AbstractA new concept of generating tight bunches of electrons accelerated to high energies is proposed. The electrons are born via ionization of a low-density neutral gas by laser radiation, and the concept is based on the electrons acceleration in traps arising within the pattern of interference of several relativistically intense laser pulses with amplitude fronts tilted relative to their phase fronts. The traps move with the speed of light and (1) collect electrons; (2) compress them to extremely high density in all dimensions, forming electron bunches; and (3) accelerate the resulting bunches to energies of at least several GeV per electron. The simulations of bunch formation employ the Newton equation with the corresponding Lorentz force.

Formation of Luminescing High-Temperature Ceramics upon Exposure to Powerful High-Energy Electron Flux

2021 ◽  
Vol 63 (9) ◽  
pp. 1615-1621
Author(s):  
V. M. Lisitsyn ◽  
L. A. Lisitsyna ◽  
M. G. Golkovskii ◽  
D. A. Musakhanov ◽  
A. V. Ermolaev
Keyword(s):  
High Temperature ◽  
Electron Flux ◽  
High Energy ◽  
Energy Electron ◽  
High Energy Electron

scholarly journals Imaging at an x-ray absorption edge using free electron laser pulses for interface dynamics in high energy density systems

2017 ◽  
Vol 88 (5) ◽  
pp. 053501 ◽  
Author(s):  
M. A. Beckwith ◽  
S. Jiang ◽  
A. Schropp ◽  
A. Fernandez-Pañella ◽  
H. G. Rinderknecht ◽  
...  
Keyword(s):  
Energy Density ◽  
Absorption Edge ◽  
Free Electron ◽  
Free Electron Laser ◽  
Laser Pulses ◽  
High Energy ◽  
High Energy Density ◽  
Interface Dynamics ◽  
X Ray ◽  
X Ray Absorption

Relativistic self-focusing of fs-laser pulses and their heating effect on the preformed plasma

2005 ◽  
Vol 33 (2) ◽  
pp. 480-481 ◽  
Author(s):  
M. Kaluza ◽  
I.B. Foldes ◽  
E. Racz ◽  
M.I.K. Santala ◽  
G.D. Tsakiris ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Heating Effect ◽  
Self Focusing ◽  
Fs Laser ◽  
Preformed Plasma
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