Fast Neutron Emission from a High-Energy Ion Beam Produced by a High-Intensity Subpicosecond Laser Pulse

AbstractFor high-energy gain of electron acceleration by a laser wakefield, a stable or guiding propagation of an ultrashort, high-intensity laser pulse in a gas-target plasma is of fundamental importance. Preliminary experiments were carried out for the propagation of 30-fs, ~100-TW laser pulses of intensities ~1019W/cm2 in plasma of densities ~1019/cm3. Self-guiding length of nearly 1.4 mm was observed in a gas jet and 15 mm in a hydrogen-filled capillary. Fluid-dynamics simulations are used to characterize the two types of gas targets. Particle-in-cell simulations indicate that in the plasma, after the pulse's evolution of self-focusing and over-focusing, the high-intensity pulse could be stably guided with a beam radius close to the plasma wavelength. At lower plasma densities, a preformed plasma channel of a parabolic density profile matched to the laser spot size would be efficient for guiding the pulse.

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Laser-driven acceleration of heavy ions at ultra-relativistic laser intensity

Laser and Particle Beams ◽

10.1017/s0263034618000563 ◽

2018 ◽

Vol 36 (4) ◽

pp. 507-512 ◽

Cited By ~ 1

Author(s):

J. Domański ◽

J. Badziak ◽

M. Marchwiany

Keyword(s):

Laser Pulse ◽

Heavy Ions ◽

Ion Beam ◽

Heavy Ion ◽

High Energy ◽

Target Thickness ◽

High Energy Density ◽

Ion Acceleration ◽

Acceleration Process ◽

Particle In Cell

AbstractThis paper presents the results of numerical investigations into the acceleration of heavy ions by a multi-PW laser pulse of ultra-relativistic intensity, to be available with the Extreme Light Infrastructure lasers currently being built in Europe. In the numerical simulations, performed with the use of a multi-dimensional (2D3V) particle-in-cell code, the thorium target with a thickness of 50 or 200 nm was irradiated by a circularly polarized 20 fs laser pulse with an energy of ~150 J and an intensity of 1023 W/cm2. It was found that the detailed run of the ion acceleration process depends on the target thickness, though in both considered cases the radiation pressure acceleration (RPA) stage of ion acceleration is followed by a sheath acceleration stage, with a significant role in the post-RPA stage being played by the ballistic movement of ions. This hybrid acceleration mechanism leads to the production of an ultra-short (sub-picosecond) multi-GeV ion beam with a wide energy spectrum and an extremely high intensity (>1021 W/cm2) and ion fluence (>1017 cm−2). Heavy ion beams of such extreme parameters are hardly achievable in conventional RF-driven ion accelerators, so they could open the avenues to new areas of research in nuclear and high energy density physics, and possibly in other scientific domains.

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Towards optimization of femtosecond laser pulse nanostructuring of targets for high-intensity laser experiments in vacuum

Applied Physics A ◽

10.1007/s00339-021-04664-w ◽

2021 ◽

Vol 127 (7) ◽

Author(s):

A. Andreev ◽

J. Imgrunt ◽

V. Braun ◽

I. Dittmar ◽

U. Teubner

Keyword(s):

Laser Pulse ◽

Femtosecond Laser ◽

High Intensity ◽

Extreme Ultraviolet ◽

Theoretical Models ◽

Laser Pulses ◽

High Energy ◽

Femtosecond Laser Pulses ◽

Laser Development ◽

Laser Experiments

AbstractThe interaction of intense femtosecond laser pulses with solid targets is a topic that has attracted a large amount of interest in science and applications. For many of the related experiments a large energy deposition or absorption as well as an efficient coupling to extreme ultraviolet (XUV), X-ray photon generation, and/or high energy particles is important. Here, much progress has been made in laser development and in experimental schemes, etc. However, regarding the improvement of the target itself, namely its geometry and surface, only limited improvements have been reported. The present paper investigates the formation of laser-induced periodic surface structures (LIPSS or ripples) on polished thick copper targets by femtosecond Ti:sapphire laser pulses. In particular, the dependence of the ripple period and ripple height has been investigated for different fluences and as a function of the number of laser shots on the same surface position. The experimental results and the formation of ripple mechanisms on metal surfaces in vacuum by femtosecond laser pulses have been analysed and the parameters of the experimentally observed “gratings” interpreted on base of theoretical models. The results have been specifically related to improve high-intensity femtosecond-laser matter interaction experiments with the goal of an enhanced particle emission (photons and high energy electrons and protons, respectively). In those experiments the presently investigated nanostructures could be generated easily in situ by multiple pre-pulses irradiated prior to a subsequent much more intense main laser pulse.

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Coulomb explosion of a cluster irradiated by a high intensity laser pulse

Laser and Particle Beams ◽

10.1017/s0263034600183211 ◽

2000 ◽

Vol 18 (3) ◽

pp. 503-506 ◽

Cited By ~ 14

Author(s):

T. ESIRKEPOV ◽

R. BINGHAM ◽

S. BULANOV ◽

T. HONDA ◽

K. NISHIHARA ◽

...

Keyword(s):

Laser Pulse ◽

High Intensity ◽

Laser Light ◽

High Energy ◽

Coulomb Explosion ◽

New Class ◽

High Intensity Laser ◽

Ion Cloud ◽

2D And 3D ◽

Intensity Laser

Clusters represent a new class of laser pulse targets which show both the properties of underdense and of overdense plasmas. We present analytical and numerical results (based on 2D- and 3D-PIC simulations) of the Coulomb explosion of the ion cloud that is formed when a cluster is irradiated by a high-intensity laser pulse. For laser pulse intensities in the range of 1021−1022 W/cm2, the laser light can rip electrons from atoms almost instantaneously and can create a cloud made of an electrically nonneutral plasma. Ions can then be accelerated up to high energy during the Coulomb explosion of the cloud.

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Ion acceleration by short high intensity laser pulse in small target sets

Laser and Particle Beams ◽

10.1017/s0263034609990115 ◽

2009 ◽

Vol 27 (3) ◽

pp. 449-457 ◽

Cited By ~ 13

Author(s):

A. Andreev ◽

K. Platonov ◽

S. Kawata

Keyword(s):

Laser Pulse ◽

Conversion Efficiency ◽

High Intensity ◽

Strong Electric Field ◽

Ion Beam ◽

Rear Surface ◽

Ion Acceleration ◽

Small Target ◽

High Intensity Laser ◽

Intensity Laser

AbstractIon acceleration by short, high intensity laser pulses in sets of small targets is treated by an analytical model developed here, and by two-dimensional particle-in-cell simulations. When an intense short laser pulse illuminates a thin foil target at normal incidence, electrons in the target are accelerated by the ponderomotive force. At the rear surface of the foil they generate a strong electric field that accelerates the ions, and generates an ion beam of small divergence. Using a mass-limited small target like a droplet enhances the ion energy, but increases divergence at the same time. In this paper, a combination of several-micron targets in a periodic structure (for example, a droplet chain) is proposed in order to increase the conversion efficiency from the incident laser beam to the emergent protons. Improvement of the energy flux conversion efficiency from the laser to the ion beam at optimal conditions is demonstrated.

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Numerical simulations of generation of high-energy ion beams driven by a petawatt femtosecond laser

Nukleonika ◽

10.1515/nuka-2015-0044 ◽

2015 ◽

Vol 60 (2) ◽

pp. 229-232

Author(s):

Jarosław Domański ◽

Jan Badziak ◽

Sławomir Jabłoński

Keyword(s):

Laser Pulse ◽

Mass Density ◽

Ion Beam ◽

High Energy ◽

Particle In Cell ◽

Ion Energies ◽

Linearly Polarized ◽

Order Of Magnitude ◽

Cell Simulation ◽

Pulse Polarization

Abstract This contribution presents results of a Particle-in-Cell simulation of ion beam acceleration via the interaction of a petawatt 25 fs laser pulse of high intensity (up to ~1021 W/cm2) with thin hydrocarbon (CH) and erbium hydride (ErH3) targets of equal areal mass density (of 0.6 g/m2). A special attention is paid to the effect that the laser pulse polarization and the material composition of the target have on the maximum ion energies and the number of high energy (>10 MeV) protons. It is shown that both the mean and the maximum ion energies are higher for the linear polarization than for the circular one. A comparison of the maximum proton energies and the total number of protons generated from the CH and ErH3 targets using a linearly polarized beam is presented. For the ErH3 targets the maximum proton energies are higher and they reach 50 MeV for the laser pulse intensity of 1021 W/cm2. The number of protons with energies higher than 10 MeV is an order of magnitude higher for the ErH3 targets than that for the CH targets.

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Temperature Field Simulation of Nitride Hard Film Irradiated by High-Intensity Pulsed Ion Beam

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.521 ◽

2011 ◽

Vol 675-677 ◽

pp. 521-524

Author(s):

Jun Chen ◽

J. Xing ◽

Li Lin ◽

Sheng Zhi Hao ◽

M.K. Lei

Keyword(s):

Pulse Duration ◽

High Intensity ◽

Short Pulse ◽

Ion Beam ◽

Solidification Process ◽

High Energy ◽

High Energy Density ◽

Experimental Result ◽

Nitride Film ◽

Short Pulse Duration

Surface treatment of hard nitride film with high-intensity pulsed ion beam (HIPIB) was investigated in the present research. On considering the high energy density and short pulse duration of HIPIB source, a one-dimension physical model was built according to the structure feature of film-base sample. It was found that the irradiation of HIPIB lead to a very fast thermal recycle of heating rate 1011K/s and cooling rate up to 1010K/s. The highest temperature located at the surface of film irradiated. When using the HIPIB parameters of accelerating voltage 350kV, pulse duration 70ns and current density 60A/cm2, the surface layer of film would be melt with depth of about 0.35mm, that was verified by the experimental result along with the grain refinement effect due to the fast solidification process.

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The Basic Physical Principles of Ion, Electron, and X-Ray Detectors and Their Application to Microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117777 ◽

1985 ◽

Vol 43 ◽

pp. 154-157

Author(s):

A.J. Tousimis

Keyword(s):

Ion Beam ◽

Depth Resolution ◽

Sample Surface ◽

High Energy ◽

X Rays ◽

X Ray ◽

Electrons And Ions ◽

Spatial Depth ◽

Minimum Surface Area ◽

Physical Principles

An integral and of prime importance of any microtopography and microanalysis instrument system is its electron, x-ray and ion detector(s). The resolution and sensitivity of the electron microscope (TEM, SEM, STEM) and microanalyzers (SIMS and electron probe x-ray microanalyzers) are closely related to those of the sensing and recording devices incorporated with them.Table I lists characteristic sensitivities, minimum surface area and depth analyzed by various methods. Smaller ion, electron and x-ray beam diameters than those listed, are possible with currently available electromagnetic or electrostatic columns. Therefore, improvements in sensitivity and spatial/depth resolution of microanalysis will follow that of the detectors. In most of these methods, the sample surface is subjected to a stationary, line or raster scanning photon, electron or ion beam. The resultant radiation: photons (low energy) or high energy (x-rays), electrons and ions are detected and analyzed.

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