Forward directed ion acceleration in a LWFA with ionization-induced injection

2012 ◽  
Vol 78 (4) ◽  
pp. 327-331 ◽  
Author(s):  
N. LEMOS ◽  
J. L. MARTINS ◽  
J. M. DIAS ◽  
K. A. MARSH ◽  
A. PAK ◽  
...  
Keyword(s):  
Forward Direction ◽  
High Energy ◽  
Plasma Boundary ◽  
Time Varying ◽  
Azimuthal Magnetic Field ◽  
Energetic Ions ◽  
Ion Energy ◽  
Particle In Cell ◽  
High Energy Electrons ◽  
Vacuum Interface

AbstractIn this work we present an experimental study where energetic ions were produced in an underdense 2.5 × 1019 cm−3 plasma created by a 50 fs Ti:Sapphire laser with 5 TWs of power. The plasma comprises 95% He and 5% N2 gases. Ionization-induced trapping of nitrogen K-shell electrons in the laser-induced wakefield generates an electron beam with a mean energy of 40 MeV and ~1 nC of charge. Some of the helium ions at the wake–vacuum interface are accelerated with a measured minimum ion energy of He1+ ions of 1.2 MeV and He2+ ions of 4 MeV. The physics of the interaction is studied with 2D particle-in-cell simulations. These reveal the formation of an ion filament on the axis of the plasma due to space charge attraction of the wakefield-accelerated high-charge electron bunch. Some of these high-energy electrons escape the plasma to form a sheath at the plasma–vacuum boundary that accelerates some of the ions in the filament in the forward direction. Electrons with energy less than the sheath potential cannot escape and return to the plasma boundary in a vortex-like motion. This in turn produces a time-varying azimuthal magnetic field, which generates a longitudinal electric field at the interface that further accelerates and collimates the ions.

scholarly journals Spatiotemporal evolution of a thin plasma foil with Kappa distribution

2014 ◽  
Vol 32 (4) ◽  
pp. 523-529 ◽  
Author(s):  
H. Mehdian ◽  
A. Kargarian ◽  
K. Hajisharifi
Keyword(s):  
Electron Distribution ◽  
Electron Distribution Function ◽  
High Energy ◽  
Spatiotemporal Evolution ◽  
Particle In Cell ◽  
High Energy Electrons ◽  
High Energy Tail ◽  
Kinetic Effects ◽  
The One ◽  
Thin Plasma

AbstractThe one-dimensional behavior of a thin plasma foil heated by laser is studied, emphasizing on the fully kinetic effects associated with initial energetic electrons using a relativistic kinetic 1D3V Particle-In-Cell code. For this purpose, the generalized Lorentzian (Kappa) function inclusive the high energy tail is employed for initial electron distribution. The presence of the initially high-energy electrons leads to a different ion energy spectrum than the initially Maxwellian distribution. It is shown for the smaller Kappa parameter k where the high energy tail of the electron distribution function becomes more significant, the electron cooling rate increases. Moreover, the spatiotemporal evolution of electric field is strongly affected by the initial super-thermal electrons.

scholarly journals Fast magnetic energy dissipation in relativistic plasma induced by high order laser modes

2016 ◽  
Vol 4 ◽  
Author(s):  
Y. J. Gu ◽  
Q. Yu ◽  
O. Klimo ◽  
T. Zh. Esirkepov ◽  
S. V. Bulanov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Magnetic Energy ◽  
Collisionless Plasma ◽  
High Energy ◽  
Field Energy ◽  
Displacement Current ◽  
Particle In Cell ◽  
Magnetic Field Energy ◽  
High Energy Electrons

Fast magnetic field annihilation in a collisionless plasma is induced by using TEM(1,0) laser pulse. The magnetic quadrupole structure formation, expansion and annihilation stages are demonstrated with 2.5-dimensional particle-in-cell simulations. The magnetic field energy is converted to the electric field and accelerate the particles inside the annihilation plane. A bunch of high energy electrons moving backwards is detected in the current sheet. The strong displacement current is the dominant contribution which induces the longitudinal inductive electric field.

scholarly journals Gamma-ray generation from ultraintense laser-irradiated solid targets with preplasma

2020 ◽  
Vol 8 ◽  
Author(s):  
Xiang-Bing Wang ◽  
Guang-Yue Hu ◽  
Zhi-Meng Zhang ◽  
Yu-Qiu Gu ◽  
Bin Zhao ◽  
...  
Keyword(s):  
Quantum Electrodynamics ◽  
Gamma Ray ◽  
High Energy ◽  
Solid Target ◽  
Laser Plasma Interaction ◽  
Particle In Cell ◽  
High Energy Electrons ◽  
Γ Rays ◽  
Γ Ray ◽  
Scale Length

Abstract In the laser plasma interaction of quantum electrodynamics (QED)-dominated regime, γ-rays are generated due to synchrotron radiation from high-energy electrons traveling in a strong background electromagnetic field. With the aid of 2D particle-in-cell code including QED physics, we investigate the preplasma effect on the γ-ray generation during the interaction between an ultraintense laser pulse and solid targets. We found that with the increasing preplasma scale length, the γ-ray emission is enhanced significantly and finally reaches a steady state. Meanwhile, the γ-ray beam becomes collimated. This shows that, in some cases, the preplasmas will be piled up acting as a plasma mirror in the underdense preplasma region, where the γ-rays are produced by the collision between the forward electrons and the reflected laser fields from the piled plasma. The piled plasma plays the same role as the usual reflection mirror made from a solid target. Thus, a single solid target with proper scale length preplasma can serve as a manufactural and robust γ-ray source.

scholarly journals Optimization for deuterium ion acceleration in foam targets by ultra-intense lasers

2010 ◽  
Vol 28 (2) ◽  
pp. 333-341 ◽  
Author(s):  
M.A. Bari ◽  
Z.M. Sheng ◽  
W.M. Wang ◽  
Y.T. Li ◽  
M. Salahuddin ◽  
...  
Keyword(s):  
High Energy ◽  
Hot Electrons ◽  
Energy Spectra ◽  
Ion Acceleration ◽  
Optimal Angle ◽  
Ion Energy ◽  
Particle In Cell ◽  
Laser Parameters ◽  
Target Composition ◽  
Electrostatic Fields

AbstractIn this article, we investigate the effects of foam target composition and laser parameters on deuterium ion energy spectra with particle-in-cell simulations. We find that localized electrostatic fields with multi peaks around the surfaces of lamellar layers inside foam target are induced. These fields accelerate deuterium ions from thin foam layers by restricting the flow of hot electrons. This mechanism of ion acceleration called as bulk ion acceleration generates large number of high energy deuterium ions. Deuterons inside foam target are accelerated up to 126 MeV in case of oblique optimal angle of 30° where it is much greater than the normal laser incidence energy of 88 MeV.

scholarly journals Generation of high-energy ion bunches via laser-induced cavity pressure acceleration at ultra-high laser intensities

2014 ◽  
Vol 32 (1) ◽  
pp. 129-135 ◽  
Author(s):  
S. Jabłoński ◽  
J. Badziak ◽  
P. Rączka
Keyword(s):  
Laser Beam ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Light Polarization ◽  
Cavity Pressure ◽  
Pure Radiation ◽  
Ion Energy ◽  
Particle In Cell ◽  
High Laser ◽  
Ion Energies

AbstractIn this paper, a new method for efficient generation of high-energy ion bunches via laser-induced cavity pressure acceleration (LICPA) is examined using one-dimensional particle-in-cell code PIC1D. It is found that for high laser beam intensities of the order of 1022 W/cm2 and for circular light polarization, a substantial increase in parameters of the accelerated ions is obtained when the target is placed inside a special cavity, into which the laser beam is introduced by a small hole. As compared to the pure radiation pressure acceleration scheme, the LICPA scheme leads to an increase in ion energies and the laser-to-ions energy conversion efficiency while the width of the ion energy spectrum are similar for both the schemes. Such a tendency was observed for all carbon targets (from 2 µm to 0.2 µm thick) investigated in the paper. The results of PIC1D simulations agree very well with predictions of the suitably generalized light sail model.

scholarly journals Towards laser ion acceleration with holed targets

2020 ◽  
Vol 86 (3) ◽  
Author(s):  
Prokopis Hadjisolomou ◽  
S. V. Bulanov ◽  
G. Korn
Keyword(s):  
Conversion Efficiency ◽  
Proton Energy ◽  
Laser Intensity ◽  
High Energy ◽  
Central Hole ◽  
Complex Geometries ◽  
Carbon Ions ◽  
High Energy Electron ◽  
Ion Energy ◽  
Particle In Cell

Although the interaction of a flat foil with currently available laser intensities is now considered a routine process, during the last decade, emphasis has been given to targets with complex geometries aiming at increasing the ion energy. This work presents a target geometry where two symmetric side holes and a central hole are drilled into the foil. A study of the various side-hole and central-hole length combinations is performed with two-dimensional particle-in-cell simulations for polyethylene targets and a laser intensity of $5.2\times 10^{21}~\text{W}~\text{cm}^{-2}$ . The holed targets show a remarkable increase of the conversion efficiency, which corresponds to a different target configuration for electrons, protons and carbon ions. Furthermore, diffraction of the laser pulse leads to a directional high energy electron beam, with a temperature of ${\sim}40~\text{MeV}$ , or seven times higher than in the case of a flat foil. The higher conversion efficiency consequently leads to a significant enhancement of the maximum proton energy from holed targets.

scholarly journals Formation of electron clouds during particle acceleration in a 3D current sheet

2010 ◽  
Vol 6 (S274) ◽  
pp. 453-457 ◽  
Author(s):  
Valentina V. Zharkova ◽  
Taras Siversky
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Spatial Separation ◽  
High Energy ◽  
X Ray ◽  
Particle In Cell ◽  
High Energy Electrons ◽  
Sufficient Energy ◽  
Electron Clouds ◽  
The Magnetic Field

AbstractAcceleration of protons and electrons in a reconnecting current sheet (RCS) is investigated with the test particle and particle-in-cell (PIC) approaches in the 3D magnetic configuration including the guiding field. PIC simulations confirm a spatial separation of electrons and protons towards the midplane and reveal that this separation occur as long as protons are getting accelerated. During this time electrons are ejected into their semispace of the current sheet moving away from the midplane to distances up to a factor of 103 – 104 of the RCS thickness and returning back to the RCS. This process of electron circulation around the current sheet midplane creates a cloud of high energy electrons around the current sheet which exists as long as protons are accelerated. Only after protons gain sufficient energy to break from the magnetic field of the RCS, they are ejected to the opposite semispace dragging accelerated electrons with them. These clouds can be the reason of hard X-ray emission in coronal sources observed by RHESSI.

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.

Sign in / Sign up

Export Citation Format

Share Document