Electron and ion acceleration by relativistic shocks: particle-in-cell simulations

AbstractWe present results of 2D particle-in-cell (PIC) simulations of carbon ion acceleration by 10 petawatt (PW) laser pulses, studying both circular polarized (CP) and linear polarized (LP) pulses. We carry out a thickness scanning of a solid carbon target to investigate the ideal thickness for carbon ion acceleration mechanisms using a 10 PW laser with an irradiance of 5 × 1022 W cm−2. The energy spectra of carbon ions and electrons and their temperature are studied. Additionally, for the carbon ions, their angular divergence is studied. It is shown that the ideal thickness for the carbon acceleration is 120 nm and the cutoff energy for carbon ions is 5 and 3 GeV for CP and LP pulses, respectively. The corresponding carbon ions temperature is ~1 and ~0.75 GeV. On the other hand, the energy cutoff for the electrons is ~500 MeV with LP and ~400 MeV with CP laser pulses. We report that the breakout afterburner mechanism is most likely causing the acceleration of carbon ions to such high energies for the optimal target thickness.

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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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KINETIC SIMULATIONS OF THE CURRENT-DRIVEN INSTABILITY IN COSMIC RAY MODIFIED RELATIVISTIC SHOCKS

International Journal of Modern Physics D ◽

10.1142/s0218271808013431 ◽

2008 ◽

Vol 17 (10) ◽

pp. 1803-1809 ◽

Cited By ~ 2

Author(s):

M. A. RIQUELME ◽

A. SPITKOVSKY

Keyword(s):

Cosmic Ray ◽

Back Reaction ◽

Speed Of Light ◽

One Dimensional ◽

Particle In Cell ◽

Nonlinear Properties ◽

Relativistic Shock ◽

Relativistic Shocks ◽

Viable Mechanism ◽

Alfven Velocity

We study the current-driven instability predicted by Bell (2004) using particle-in-cell simulations. We use one-dimensional simulations to test the dispersion relation and the nonlinear properties of the instability for the case of a relativistic shock front under idealized conditions. We find that if the cosmic rays (CR) are energetic enough to not get deflected by the generated magnetic field, the instability can grow exponentially until the Alfvén velocity of the plasma becomes comparable to the speed of light. We also use one- and two-dimensional simulations to study the effect of the back reaction of the instability on CR. We find that the deflection and filamentation of CR and background plasma play an important role in the saturation of the instability. The current-driven instability is a viable mechanism for the amplification of magnetic fields in both non-relativistic and relativistic shock environments.

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A particle-in-cell code comparison for ion acceleration: EPOCH, LSP, and WarpX

Physics of Plasmas ◽

10.1063/5.0053109 ◽

2021 ◽

Vol 28 (7) ◽

pp. 074505

Author(s):

Joseph R. Smith ◽

Chris Orban ◽

Nashad Rahman ◽

Brendan McHugh ◽

Ricky Oropeza ◽

...

Keyword(s):

Ion Acceleration ◽

Particle In Cell ◽

Code Comparison

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Particle-in-cell simulations of ion acceleration in high contrast and high intensity laser-solid target interactions at intensities above 1020 Wcm-2*

2017 IEEE International Conference on Plasma Science (ICOPS) ◽

10.1109/plasma.2017.8496172 ◽

2017 ◽

Author(s):

J. Li ◽

P. Forestier-Colleoni ◽

C. McGuffey ◽

F.N. Beg ◽

A. Arefiev ◽

...

Keyword(s):

High Intensity ◽

Ion Acceleration ◽

Solid Target ◽

High Contrast ◽

Particle In Cell ◽

High Intensity Laser ◽

Intensity Laser

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Preferential enhancement of laser-driven carbon ion acceleration from optimized nanostructured surfaces

Scientific Reports ◽

10.1038/srep11930 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 12

Author(s):

Malay Dalui ◽

W.-M. Wang ◽

T. Madhu Trivikram ◽

Subhrangsu Sarkar ◽

Sheroy Tata ◽

...

Keyword(s):

Laser Pulses ◽

Ultrashort Laser Pulses ◽

Ion Acceleration ◽

Maximum Acceleration ◽

Carbon Ion ◽

Nanostructured Surfaces ◽

Particle In Cell ◽

Dense Plasmas ◽

Copper Target ◽

Sputter Deposited

Abstract High-intensity ultrashort laser pulses focused on metal targets readily generate hot dense plasmas which accelerate ions efficiently and can pave way to compact table-top accelerators. Laser-driven ion acceleration studies predominantly focus on protons, which experience the maximum acceleration owing to their highest charge-to-mass ratio. The possibility of tailoring such schemes for the preferential acceleration of a particular ion species is very much desired but has hardly been explored. Here, we present an experimental demonstration of how the nanostructuring of a copper target can be optimized for enhanced carbon ion acceleration over protons or Cu-ions. Specifically, a thin (≈0.25 μm) layer of 25–30 nm diameter Cu nanoparticles, sputter-deposited on a polished Cu-substrate, enhances the carbon ion energy by about 10-fold at a laser intensity of 1.2×1018 W/cm2. However, particles smaller than 20 nm have an adverse effect on the ion acceleration. Particle-in-cell simulations provide definite pointers regarding the size of nanoparticles necessary for maximizing the ion acceleration. The inherent contrast of the laser pulse is found to play an important role in the species selective ion acceleration.

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Relativistic Jet Simulations of the Weibel Instability in the Slab Model to Cylindrical Jets with Helical Magnetic Fields

10.20944/preprints201811.0374.v2 ◽

2018 ◽

Author(s):

Ken-Ichi Nishikawa ◽

Yosuke Mizuno ◽

Jose l. Gomez ◽

Ioana Dutan ◽

Athina Meli ◽

...

Keyword(s):

Relativistic Jets ◽

Weibel Instability ◽

Particle In Cell ◽

Relativistic Shocks ◽

Relativistic Jet ◽

The Us ◽

Field Geometry ◽

Solar Plasmas ◽

Pic Method ◽

Helical Magnetic Field

The Particle-In-Cell (PIC) method has been developed in order to investigate microscopic phenomena, and with the advances of computing power, newly developed codes have been used for several fields such as astrophysical, magnetospheric, and solar plasmas. PIC applications have grown extensively with large computing powers available on supercomputers such as Pleiades and Blue Waters in the US. For astrophysical plasma research PIC methods have been utilized for several topics such as reconnection, pulsar dynamics, non-relativistic shocks, relativistic shocks, relativistic jets, etc. PIC simulations of relativistic jets have been reviewed with the emphasis on the physics involved in the simulations. This review summarizes PIC simulations, starting with the Weibel instability in slab models of jets, and then focuses on global jet evolution in helical magnetic field geometry. In particular we address kinetic Kelvin-Helmholtz instabilities and mushroom instabilities.

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