Generation of fast charged particles and superstrong magnetic fields in the interaction of ultrashort high-intensity laser pulses with solid targets

Abstract

Recent experimental and theoretical investigations are reviewed concerning the generation of fast charged particles and superstrong magnetic fields in the interaction of ultrashort laser pulses with solid targets. The mechanisms of generating fast charged particles in superstrong light fields of laser radiation with intensities ranging from 10 17 to 10 21 W cm ±2 are considered. Electron acceleration due to vacuum heating, the ponderomotive potential, resonance absorption, the laserdriven wake field in the underdense part of plasma, cyclotron mechanism and some other mechanisms are thoroughly analyzed. Experimental data on the acceleration of protons and atomic ions by spatial charge fields on thin and thick solid targets are presented and theoretically interpreted. Particular attention is paid to the generation of superstrong quasistatic magnetic fields in laser plasmas and methods for measuring them under the action of various laser pulses of both femtoand picosecond durations. The possible formation of magnetic plasma configurations and magnetic plasma confinement are discussed.

Radiation from particles moving in small-scale magnetic fields created in solid-density laser-plasma laboratory experiments

“…This is comparable to the PIC simulation (final) "effective" electron temperature 300-600 keV. The laser generated Weibel magnetic field is predicted to have the maximum value 12 …”

“…[8][9][10][11] These magnetic fields can be generated by a number of mechanisms-e.g., by the misalignment in plasma temperature and density gradients (Biermann Battery), or by an induction field produced by the flux of fast electrons via the ponderomotive acceleration. 12 At relativistic intensities (>10 18 W/cm 2 ) and ultrashort pulse durations (<1 ps), magnetic fields can also be generated via an electron-driven Weibel-like instability. 2,12 Unlike the pure Weibel instability driven by the plasma temperature anisotropy, 13 this Weibellike instability is initiated by counterstreaming electron beams 14 consisting of a "hot" beam (arising immediately following the target's interaction with the high-intensity laser) and a returning (shielding) "cold" electron beam.…”

“…12 At relativistic intensities (>10 18 W/cm 2 ) and ultrashort pulse durations (<1 ps), magnetic fields can also be generated via an electron-driven Weibel-like instability. 2,12 Unlike the pure Weibel instability driven by the plasma temperature anisotropy, 13 this Weibellike instability is initiated by counterstreaming electron beams 14 consisting of a "hot" beam (arising immediately following the target's interaction with the high-intensity laser) and a returning (shielding) "cold" electron beam. Initially, the net current is zero; however, the Weibel-like instability subsequently grows, leading to the formation of separated current filaments-the source of a quasi-static magnetic field configuration.…”

Direct observation of turbulent magnetic fields in hot, dense laser produced plasmas

“…intense laser matter interaction | high energy density | astrophysical simulations | filamentary structures T he largest terrestrially available magnetic fields are generated when an intense laser pulse (intensity above 10 18 W∕cm 2 ) irradiates a solid target (1)(2)(3). The high energy density produced by laser irradiation generates relativistic electron jets, through the process of wave breaking.…”

The Matter in Extreme Conditions instrument at the Linac Coherent Light Source

“…The high laser intensities required to create it can generate electrons with relativistic velocity distributions, an active research field in itself. The hot electrons are at the origin of various secondary sources such as proton beams, ion beams (Belyaev et al, 2008) or X-rays (Murnane et al, 1991). They can be used to isochorically heat matter (Hoarty et al, 2007), be the spark in the fast ignition approach (Tabak et al, 1994) to inertial confinement fusion or be used to model astrophysical systems (Mondal et al, 2012).…”