Laser-induced breakdown spectroscopy is reviewed by dividing the literature into three categories according to target phase: solid, liquid, or gas. Within each category, the literature is ...

Fundamentals and Applications of Laser-Induced Breakdown Spectroscopy

A distinctive way of quantitatively imaging inertial fusion implosions has resulted in the characterization of two different types of electromagnetic configurations and in the measurement of the temporal evolution of capsule size and areal density. Radiography with a pulsed, monoenergetic, isotropic proton source reveals field structures through deflection of proton trajectories, and areal densities are quantified through the energy lost by protons while traversing the plasma. The two field structures consist of (i) many radial filaments with complex striations and bifurcations, permeating the entire field of view, of magnetic field magnitude 60 tesla and (ii) a coherent, centrally directed electric field of order 10 9 volts per meter, seen in proximity to the capsule surface. Although the mechanism for generating these fields is unclear, their effect on implosion dynamics is potentially consequential.

/pdf/proton-radiography-of-inertial-fusion-implosions-n9sbm34ffj.pdf

Proton Radiography of Inertial Fusion Implosions

The evolution of laboratory produced magnetic jets is followed numerically through three-dimensional, nonideal magnetohydrodynamic simulations. The experiments are designed to study the interaction of a purely toroidal field with an extended plasma background medium. The system is observed to evolve into a structure consisting of an approximately cylindrical magnetic cavity with an embedded magnetically confined jet on its axis. The supersonic expansion produces a shell of swept-up shocked plasma that surrounds and partially confines the magnetic tower. Currents initially flow along the walls of the cavity and in the jet but the development of current-driven instabilities leads to the disruption of the jet and a rearrangement of the field and currents. The top of the cavity breaks up, and a well-collimated, radiatively cooled, “clumpy” jet emerges from the system.

http://amrel.obspm.fr/~stehle/lap/pages/EN/publications/2007ArxivCiardi.pdf

The evolution of Magnetic Tower Jets in the Laboratory

Effects related to the use of high power and repetition rate lasers in ablation of metals and silicon were investigated. Numeric simulation and experiments were performed to find out conditions of the efficient use of laser energy. Accumulation of defects lowers the ablation threshold when a high pulse-repetition rate is applied. An optimum beam waist exists for certain pulse energy to maximize the ablation but the waist does not allow achieving a high processing accuracy. Energy efficiency of the laser processing falls down when pulse energy exceeds the material dependant limit. Plasma shielding was assumed to be the main limiting factor in processing efficiency of metals with the high power picosecond lasers. Intelligent control of process parameters is required to keep optimal conditions for the material removal by laser ablation.

/pdf/use-of-high-repetition-rate-and-high-power-lasers-in-1aryilpbrd.pdf

Use of High Repetition Rate and High Power Lasers in Microfabrication: How to Keep the Efficiency High?

A new laser-driven ion acceleration mechanism has been identified in particle-in-cell simulations of high-contrast-ratio ultraintense lasers with very thin (10s of nm) solid targets [Yin et al., Laser and Particle Beams 24, 291 (2006); Yin et al., Phys. Plasmas 13, 072701 (2007)]. After a brief period of target normal sheath acceleration (TNSA), “enhanced” TNSA follows. In this stage, the laser rapidly heats all the electrons in the target as the target thickness becomes comparable to the skin depth and enhanced acceleration of the ions results. Then, concomitant with the laser penetrating the target, a large accelerating longitudinal electric field is generated that co-moves with the ions. This last phase has been termed the laser “breakout afterburner” (BOA). Earlier work suggested that the BOA was associated with the Buneman instability that efficiently converts energy from the drift of the electrons into the ions. In this Brief Communication, this conjecture is found to be consistent with particle-in-...

Relativistic Buneman instability in the laser breakout afterburner

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0263034600007618

Editor: I. I. Sobelman. X-Ray Plasma Spectroscopy and the Properties of Multi-Charged Ions (Volume 179, Proceedings of the Lebedev Physics Institute), (NOVA Science Publishers, Inc., New York, 1988) 256 pages, $87.00

B Yaakobi

Papers

Editor: I. I. Sobelman. X-Ray Plasma Spectroscopy and the Properties of Multi-Charged Ions (Volume 179, Proceedings of the Lebedev Physics Institute), (NOVA Science Publishers, Inc., New York, 1988) 256 pages, $87.00